ref: 76bf681338ee60fa90eb64f5832161686aa6c792
dir: /third_party/nestegg/src/nestegg.c/
/*
* Copyright © 2010 Mozilla Foundation
*
* This program is made available under an ISC-style license. See the
* accompanying file LICENSE for details.
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "third_party/nestegg/halloc/halloc.h"
#include "third_party/nestegg/include/nestegg/nestegg.h"
/* EBML Elements */
#define ID_EBML 0x1a45dfa3
#define ID_EBML_VERSION 0x4286
#define ID_EBML_READ_VERSION 0x42f7
#define ID_EBML_MAX_ID_LENGTH 0x42f2
#define ID_EBML_MAX_SIZE_LENGTH 0x42f3
#define ID_DOCTYPE 0x4282
#define ID_DOCTYPE_VERSION 0x4287
#define ID_DOCTYPE_READ_VERSION 0x4285
/* Global Elements */
#define ID_VOID 0xec
#define ID_CRC32 0xbf
/* WebM Elements */
#define ID_SEGMENT 0x18538067
/* Seek Head Elements */
#define ID_SEEK_HEAD 0x114d9b74
#define ID_SEEK 0x4dbb
#define ID_SEEK_ID 0x53ab
#define ID_SEEK_POSITION 0x53ac
/* Info Elements */
#define ID_INFO 0x1549a966
#define ID_TIMECODE_SCALE 0x2ad7b1
#define ID_DURATION 0x4489
/* Cluster Elements */
#define ID_CLUSTER 0x1f43b675
#define ID_TIMECODE 0xe7
#define ID_BLOCK_GROUP 0xa0
#define ID_SIMPLE_BLOCK 0xa3
/* BlockGroup Elements */
#define ID_BLOCK 0xa1
#define ID_BLOCK_DURATION 0x9b
#define ID_REFERENCE_BLOCK 0xfb
#define ID_DISCARD_PADDING 0x75a2
/* Tracks Elements */
#define ID_TRACKS 0x1654ae6b
#define ID_TRACK_ENTRY 0xae
#define ID_TRACK_NUMBER 0xd7
#define ID_TRACK_UID 0x73c5
#define ID_TRACK_TYPE 0x83
#define ID_FLAG_ENABLED 0xb9
#define ID_FLAG_DEFAULT 0x88
#define ID_FLAG_LACING 0x9c
#define ID_TRACK_TIMECODE_SCALE 0x23314f
#define ID_LANGUAGE 0x22b59c
#define ID_CODEC_ID 0x86
#define ID_CODEC_PRIVATE 0x63a2
#define ID_CODEC_DELAY 0x56aa
#define ID_SEEK_PREROLL 0x56bb
/* Video Elements */
#define ID_VIDEO 0xe0
#define ID_STEREO_MODE 0x53b8
#define ID_PIXEL_WIDTH 0xb0
#define ID_PIXEL_HEIGHT 0xba
#define ID_PIXEL_CROP_BOTTOM 0x54aa
#define ID_PIXEL_CROP_TOP 0x54bb
#define ID_PIXEL_CROP_LEFT 0x54cc
#define ID_PIXEL_CROP_RIGHT 0x54dd
#define ID_DISPLAY_WIDTH 0x54b0
#define ID_DISPLAY_HEIGHT 0x54ba
/* Audio Elements */
#define ID_AUDIO 0xe1
#define ID_SAMPLING_FREQUENCY 0xb5
#define ID_CHANNELS 0x9f
#define ID_BIT_DEPTH 0x6264
/* Cues Elements */
#define ID_CUES 0x1c53bb6b
#define ID_CUE_POINT 0xbb
#define ID_CUE_TIME 0xb3
#define ID_CUE_TRACK_POSITIONS 0xb7
#define ID_CUE_TRACK 0xf7
#define ID_CUE_CLUSTER_POSITION 0xf1
#define ID_CUE_BLOCK_NUMBER 0x5378
/* EBML Types */
enum ebml_type_enum {
TYPE_UNKNOWN,
TYPE_MASTER,
TYPE_UINT,
TYPE_FLOAT,
TYPE_INT,
TYPE_STRING,
TYPE_BINARY
};
#define LIMIT_STRING (1 << 20)
#define LIMIT_BINARY (1 << 24)
#define LIMIT_BLOCK (1 << 30)
#define LIMIT_FRAME (1 << 28)
/* Field Flags */
#define DESC_FLAG_NONE 0
#define DESC_FLAG_MULTI (1 << 0)
#define DESC_FLAG_SUSPEND (1 << 1)
#define DESC_FLAG_OFFSET (1 << 2)
/* Block Header Flags */
#define BLOCK_FLAGS_LACING 6
/* Lacing Constants */
#define LACING_NONE 0
#define LACING_XIPH 1
#define LACING_FIXED 2
#define LACING_EBML 3
/* Track Types */
#define TRACK_TYPE_VIDEO 1
#define TRACK_TYPE_AUDIO 2
/* Track IDs */
#define TRACK_ID_VP8 "V_VP8"
#define TRACK_ID_VP9 "V_VP9"
#define TRACK_ID_VORBIS "A_VORBIS"
#define TRACK_ID_OPUS "A_OPUS"
enum vint_mask {
MASK_NONE,
MASK_FIRST_BIT
};
struct ebml_binary {
unsigned char * data;
size_t length;
};
struct ebml_list_node {
struct ebml_list_node * next;
uint64_t id;
void * data;
};
struct ebml_list {
struct ebml_list_node * head;
struct ebml_list_node * tail;
};
struct ebml_type {
union ebml_value {
uint64_t u;
double f;
int64_t i;
char * s;
struct ebml_binary b;
} v;
enum ebml_type_enum type;
int read;
};
/* EBML Definitions */
struct ebml {
struct ebml_type ebml_version;
struct ebml_type ebml_read_version;
struct ebml_type ebml_max_id_length;
struct ebml_type ebml_max_size_length;
struct ebml_type doctype;
struct ebml_type doctype_version;
struct ebml_type doctype_read_version;
};
/* Matroksa Definitions */
struct seek {
struct ebml_type id;
struct ebml_type position;
};
struct seek_head {
struct ebml_list seek;
};
struct info {
struct ebml_type timecode_scale;
struct ebml_type duration;
};
struct block_group {
struct ebml_type duration;
struct ebml_type reference_block;
struct ebml_type discard_padding;
};
struct cluster {
struct ebml_type timecode;
struct ebml_list block_group;
};
struct video {
struct ebml_type stereo_mode;
struct ebml_type pixel_width;
struct ebml_type pixel_height;
struct ebml_type pixel_crop_bottom;
struct ebml_type pixel_crop_top;
struct ebml_type pixel_crop_left;
struct ebml_type pixel_crop_right;
struct ebml_type display_width;
struct ebml_type display_height;
};
struct audio {
struct ebml_type sampling_frequency;
struct ebml_type channels;
struct ebml_type bit_depth;
};
struct track_entry {
struct ebml_type number;
struct ebml_type uid;
struct ebml_type type;
struct ebml_type flag_enabled;
struct ebml_type flag_default;
struct ebml_type flag_lacing;
struct ebml_type track_timecode_scale;
struct ebml_type language;
struct ebml_type codec_id;
struct ebml_type codec_private;
struct ebml_type codec_delay;
struct ebml_type seek_preroll;
struct video video;
struct audio audio;
};
struct tracks {
struct ebml_list track_entry;
};
struct cue_track_positions {
struct ebml_type track;
struct ebml_type cluster_position;
struct ebml_type block_number;
};
struct cue_point {
struct ebml_type time;
struct ebml_list cue_track_positions;
};
struct cues {
struct ebml_list cue_point;
};
struct segment {
struct ebml_list seek_head;
struct info info;
struct ebml_list cluster;
struct tracks tracks;
struct cues cues;
};
/* Misc. */
struct pool_ctx {
char dummy;
};
struct list_node {
struct list_node * previous;
struct ebml_element_desc * node;
unsigned char * data;
};
struct saved_state {
int64_t stream_offset;
struct list_node * ancestor;
uint64_t last_id;
uint64_t last_size;
int last_valid;
};
struct frame {
unsigned char * data;
size_t length;
struct frame * next;
};
/* Public (opaque) Structures */
struct nestegg {
nestegg_io * io;
nestegg_log log;
struct pool_ctx * alloc_pool;
uint64_t last_id;
uint64_t last_size;
int last_valid;
struct list_node * ancestor;
struct ebml ebml;
struct segment segment;
int64_t segment_offset;
unsigned int track_count;
};
struct nestegg_packet {
uint64_t track;
uint64_t timecode;
struct frame * frame;
int64_t discard_padding;
};
/* Element Descriptor */
struct ebml_element_desc {
char const * name;
uint64_t id;
enum ebml_type_enum type;
size_t offset;
unsigned int flags;
struct ebml_element_desc * children;
size_t size;
size_t data_offset;
};
#define E_FIELD(ID, TYPE, STRUCT, FIELD) \
{ #ID, ID, TYPE, offsetof(STRUCT, FIELD), DESC_FLAG_NONE, NULL, 0, 0 }
#define E_MASTER(ID, TYPE, STRUCT, FIELD) \
{ #ID, ID, TYPE, offsetof(STRUCT, FIELD), DESC_FLAG_MULTI, ne_ ## FIELD ## _elements, \
sizeof(struct FIELD), 0 }
#define E_SINGLE_MASTER_O(ID, TYPE, STRUCT, FIELD) \
{ #ID, ID, TYPE, offsetof(STRUCT, FIELD), DESC_FLAG_OFFSET, ne_ ## FIELD ## _elements, 0, \
offsetof(STRUCT, FIELD ## _offset) }
#define E_SINGLE_MASTER(ID, TYPE, STRUCT, FIELD) \
{ #ID, ID, TYPE, offsetof(STRUCT, FIELD), DESC_FLAG_NONE, ne_ ## FIELD ## _elements, 0, 0 }
#define E_SUSPEND(ID, TYPE) \
{ #ID, ID, TYPE, 0, DESC_FLAG_SUSPEND, NULL, 0, 0 }
#define E_LAST \
{ NULL, 0, 0, 0, DESC_FLAG_NONE, NULL, 0, 0 }
/* EBML Element Lists */
static struct ebml_element_desc ne_ebml_elements[] = {
E_FIELD(ID_EBML_VERSION, TYPE_UINT, struct ebml, ebml_version),
E_FIELD(ID_EBML_READ_VERSION, TYPE_UINT, struct ebml, ebml_read_version),
E_FIELD(ID_EBML_MAX_ID_LENGTH, TYPE_UINT, struct ebml, ebml_max_id_length),
E_FIELD(ID_EBML_MAX_SIZE_LENGTH, TYPE_UINT, struct ebml, ebml_max_size_length),
E_FIELD(ID_DOCTYPE, TYPE_STRING, struct ebml, doctype),
E_FIELD(ID_DOCTYPE_VERSION, TYPE_UINT, struct ebml, doctype_version),
E_FIELD(ID_DOCTYPE_READ_VERSION, TYPE_UINT, struct ebml, doctype_read_version),
E_LAST
};
/* WebM Element Lists */
static struct ebml_element_desc ne_seek_elements[] = {
E_FIELD(ID_SEEK_ID, TYPE_BINARY, struct seek, id),
E_FIELD(ID_SEEK_POSITION, TYPE_UINT, struct seek, position),
E_LAST
};
static struct ebml_element_desc ne_seek_head_elements[] = {
E_MASTER(ID_SEEK, TYPE_MASTER, struct seek_head, seek),
E_LAST
};
static struct ebml_element_desc ne_info_elements[] = {
E_FIELD(ID_TIMECODE_SCALE, TYPE_UINT, struct info, timecode_scale),
E_FIELD(ID_DURATION, TYPE_FLOAT, struct info, duration),
E_LAST
};
static struct ebml_element_desc ne_block_group_elements[] = {
E_SUSPEND(ID_BLOCK, TYPE_BINARY),
E_FIELD(ID_BLOCK_DURATION, TYPE_UINT, struct block_group, duration),
E_FIELD(ID_REFERENCE_BLOCK, TYPE_INT, struct block_group, reference_block),
E_FIELD(ID_DISCARD_PADDING, TYPE_INT, struct block_group, discard_padding),
E_LAST
};
static struct ebml_element_desc ne_cluster_elements[] = {
E_FIELD(ID_TIMECODE, TYPE_UINT, struct cluster, timecode),
E_MASTER(ID_BLOCK_GROUP, TYPE_MASTER, struct cluster, block_group),
E_SUSPEND(ID_SIMPLE_BLOCK, TYPE_BINARY),
E_LAST
};
static struct ebml_element_desc ne_video_elements[] = {
E_FIELD(ID_STEREO_MODE, TYPE_UINT, struct video, stereo_mode),
E_FIELD(ID_PIXEL_WIDTH, TYPE_UINT, struct video, pixel_width),
E_FIELD(ID_PIXEL_HEIGHT, TYPE_UINT, struct video, pixel_height),
E_FIELD(ID_PIXEL_CROP_BOTTOM, TYPE_UINT, struct video, pixel_crop_bottom),
E_FIELD(ID_PIXEL_CROP_TOP, TYPE_UINT, struct video, pixel_crop_top),
E_FIELD(ID_PIXEL_CROP_LEFT, TYPE_UINT, struct video, pixel_crop_left),
E_FIELD(ID_PIXEL_CROP_RIGHT, TYPE_UINT, struct video, pixel_crop_right),
E_FIELD(ID_DISPLAY_WIDTH, TYPE_UINT, struct video, display_width),
E_FIELD(ID_DISPLAY_HEIGHT, TYPE_UINT, struct video, display_height),
E_LAST
};
static struct ebml_element_desc ne_audio_elements[] = {
E_FIELD(ID_SAMPLING_FREQUENCY, TYPE_FLOAT, struct audio, sampling_frequency),
E_FIELD(ID_CHANNELS, TYPE_UINT, struct audio, channels),
E_FIELD(ID_BIT_DEPTH, TYPE_UINT, struct audio, bit_depth),
E_LAST
};
static struct ebml_element_desc ne_track_entry_elements[] = {
E_FIELD(ID_TRACK_NUMBER, TYPE_UINT, struct track_entry, number),
E_FIELD(ID_TRACK_UID, TYPE_UINT, struct track_entry, uid),
E_FIELD(ID_TRACK_TYPE, TYPE_UINT, struct track_entry, type),
E_FIELD(ID_FLAG_ENABLED, TYPE_UINT, struct track_entry, flag_enabled),
E_FIELD(ID_FLAG_DEFAULT, TYPE_UINT, struct track_entry, flag_default),
E_FIELD(ID_FLAG_LACING, TYPE_UINT, struct track_entry, flag_lacing),
E_FIELD(ID_TRACK_TIMECODE_SCALE, TYPE_FLOAT, struct track_entry, track_timecode_scale),
E_FIELD(ID_LANGUAGE, TYPE_STRING, struct track_entry, language),
E_FIELD(ID_CODEC_ID, TYPE_STRING, struct track_entry, codec_id),
E_FIELD(ID_CODEC_PRIVATE, TYPE_BINARY, struct track_entry, codec_private),
E_FIELD(ID_CODEC_DELAY, TYPE_UINT, struct track_entry, codec_delay),
E_FIELD(ID_SEEK_PREROLL, TYPE_UINT, struct track_entry, seek_preroll),
E_SINGLE_MASTER(ID_VIDEO, TYPE_MASTER, struct track_entry, video),
E_SINGLE_MASTER(ID_AUDIO, TYPE_MASTER, struct track_entry, audio),
E_LAST
};
static struct ebml_element_desc ne_tracks_elements[] = {
E_MASTER(ID_TRACK_ENTRY, TYPE_MASTER, struct tracks, track_entry),
E_LAST
};
static struct ebml_element_desc ne_cue_track_positions_elements[] = {
E_FIELD(ID_CUE_TRACK, TYPE_UINT, struct cue_track_positions, track),
E_FIELD(ID_CUE_CLUSTER_POSITION, TYPE_UINT, struct cue_track_positions, cluster_position),
E_FIELD(ID_CUE_BLOCK_NUMBER, TYPE_UINT, struct cue_track_positions, block_number),
E_LAST
};
static struct ebml_element_desc ne_cue_point_elements[] = {
E_FIELD(ID_CUE_TIME, TYPE_UINT, struct cue_point, time),
E_MASTER(ID_CUE_TRACK_POSITIONS, TYPE_MASTER, struct cue_point, cue_track_positions),
E_LAST
};
static struct ebml_element_desc ne_cues_elements[] = {
E_MASTER(ID_CUE_POINT, TYPE_MASTER, struct cues, cue_point),
E_LAST
};
static struct ebml_element_desc ne_segment_elements[] = {
E_MASTER(ID_SEEK_HEAD, TYPE_MASTER, struct segment, seek_head),
E_SINGLE_MASTER(ID_INFO, TYPE_MASTER, struct segment, info),
E_MASTER(ID_CLUSTER, TYPE_MASTER, struct segment, cluster),
E_SINGLE_MASTER(ID_TRACKS, TYPE_MASTER, struct segment, tracks),
E_SINGLE_MASTER(ID_CUES, TYPE_MASTER, struct segment, cues),
E_LAST
};
static struct ebml_element_desc ne_top_level_elements[] = {
E_SINGLE_MASTER(ID_EBML, TYPE_MASTER, nestegg, ebml),
E_SINGLE_MASTER_O(ID_SEGMENT, TYPE_MASTER, nestegg, segment),
E_LAST
};
#undef E_FIELD
#undef E_MASTER
#undef E_SINGLE_MASTER_O
#undef E_SINGLE_MASTER
#undef E_SUSPEND
#undef E_LAST
static struct pool_ctx *
ne_pool_init(void)
{
struct pool_ctx * pool;
pool = h_malloc(sizeof(*pool));
if (!pool)
abort();
return pool;
}
static void
ne_pool_destroy(struct pool_ctx * pool)
{
h_free(pool);
}
static void *
ne_pool_alloc(size_t size, struct pool_ctx * pool)
{
void * p;
p = h_malloc(size);
if (!p)
abort();
hattach(p, pool);
memset(p, 0, size);
return p;
}
static void *
ne_alloc(size_t size)
{
void * p;
p = calloc(1, size);
if (!p)
abort();
return p;
}
static int
ne_io_read(nestegg_io * io, void * buffer, size_t length)
{
return io->read(buffer, length, io->userdata);
}
static int
ne_io_seek(nestegg_io * io, int64_t offset, int whence)
{
return io->seek(offset, whence, io->userdata);
}
static int
ne_io_read_skip(nestegg_io * io, size_t length)
{
size_t get;
unsigned char buf[8192];
int r = 1;
while (length > 0) {
get = length < sizeof(buf) ? length : sizeof(buf);
r = ne_io_read(io, buf, get);
if (r != 1)
break;
length -= get;
}
return r;
}
static int64_t
ne_io_tell(nestegg_io * io)
{
return io->tell(io->userdata);
}
static int
ne_bare_read_vint(nestegg_io * io, uint64_t * value, uint64_t * length, enum vint_mask maskflag)
{
int r;
unsigned char b;
size_t maxlen = 8;
unsigned int count = 1, mask = 1 << 7;
r = ne_io_read(io, &b, 1);
if (r != 1)
return r;
while (count < maxlen) {
if ((b & mask) != 0)
break;
mask >>= 1;
count += 1;
}
if (length)
*length = count;
*value = b;
if (maskflag == MASK_FIRST_BIT)
*value = b & ~mask;
while (--count) {
r = ne_io_read(io, &b, 1);
if (r != 1)
return r;
*value <<= 8;
*value |= b;
}
return 1;
}
static int
ne_read_id(nestegg_io * io, uint64_t * value, uint64_t * length)
{
return ne_bare_read_vint(io, value, length, MASK_NONE);
}
static int
ne_read_vint(nestegg_io * io, uint64_t * value, uint64_t * length)
{
return ne_bare_read_vint(io, value, length, MASK_FIRST_BIT);
}
static int
ne_read_svint(nestegg_io * io, int64_t * value, uint64_t * length)
{
int r;
uint64_t uvalue;
uint64_t ulength;
int64_t svint_subtr[] = {
0x3f, 0x1fff,
0xfffff, 0x7ffffff,
0x3ffffffffLL, 0x1ffffffffffLL,
0xffffffffffffLL, 0x7fffffffffffffLL
};
r = ne_bare_read_vint(io, &uvalue, &ulength, MASK_FIRST_BIT);
if (r != 1)
return r;
*value = uvalue - svint_subtr[ulength - 1];
if (length)
*length = ulength;
return r;
}
static int
ne_read_uint(nestegg_io * io, uint64_t * val, uint64_t length)
{
unsigned char b;
int r;
if (length == 0 || length > 8)
return -1;
r = ne_io_read(io, &b, 1);
if (r != 1)
return r;
*val = b;
while (--length) {
r = ne_io_read(io, &b, 1);
if (r != 1)
return r;
*val <<= 8;
*val |= b;
}
return 1;
}
static int
ne_read_int(nestegg_io * io, int64_t * val, uint64_t length)
{
int r;
uint64_t uval, base;
r = ne_read_uint(io, &uval, length);
if (r != 1)
return r;
if (length < sizeof(int64_t)) {
base = 1;
base <<= length * 8 - 1;
if (uval >= base) {
base = 1;
base <<= length * 8;
} else {
base = 0;
}
*val = uval - base;
} else {
*val = (int64_t) uval;
}
return 1;
}
static int
ne_read_float(nestegg_io * io, double * val, uint64_t length)
{
union {
uint64_t u;
float f;
double d;
} value;
int r;
/* Length == 10 not implemented. */
if (length != 4 && length != 8)
return -1;
r = ne_read_uint(io, &value.u, length);
if (r != 1)
return r;
if (length == 4)
*val = value.f;
else
*val = value.d;
return 1;
}
static int
ne_read_string(nestegg * ctx, char ** val, uint64_t length)
{
char * str;
int r;
const size_t alloc_size = (size_t)length + 1;
if (length == 0 || length > LIMIT_STRING)
return -1;
str = ne_pool_alloc(alloc_size, ctx->alloc_pool);
r = ne_io_read(ctx->io, (unsigned char *) str, alloc_size - 1);
if (r != 1)
return r;
str[alloc_size - 1] = '\0';
*val = str;
return 1;
}
static int
ne_read_binary(nestegg * ctx, struct ebml_binary * val, uint64_t length)
{
if (length == 0 || length > LIMIT_BINARY)
return -1;
val->length = (size_t)length;
val->data = ne_pool_alloc(val->length, ctx->alloc_pool);
return ne_io_read(ctx->io, val->data, val->length);
}
static int
ne_get_uint(struct ebml_type type, uint64_t * value)
{
if (!type.read)
return -1;
assert(type.type == TYPE_UINT);
*value = type.v.u;
return 0;
}
static int
ne_get_uint32(struct ebml_type type, unsigned int * value)
{
uint64_t v;
if (ne_get_uint(type, &v))
return -1;
assert((unsigned int)v == v);
*value = (unsigned int)v;
return 0;
}
static int
ne_get_float(struct ebml_type type, double * value)
{
if (!type.read)
return -1;
assert(type.type == TYPE_FLOAT);
*value = type.v.f;
return 0;
}
static int
ne_get_string(struct ebml_type type, char ** value)
{
if (!type.read)
return -1;
assert(type.type == TYPE_STRING);
*value = type.v.s;
return 0;
}
static int
ne_get_binary(struct ebml_type type, struct ebml_binary * value)
{
if (!type.read)
return -1;
assert(type.type == TYPE_BINARY);
*value = type.v.b;
return 0;
}
static int
ne_is_ancestor_element(uint64_t id, struct list_node * ancestor)
{
struct ebml_element_desc * element;
for (; ancestor; ancestor = ancestor->previous)
for (element = ancestor->node; element->id; ++element)
if (element->id == id)
return 1;
return 0;
}
static struct ebml_element_desc *
ne_find_element(uint64_t id, struct ebml_element_desc * elements)
{
struct ebml_element_desc * element;
for (element = elements; element->id; ++element)
if (element->id == id)
return element;
return NULL;
}
static void
ne_ctx_push(nestegg * ctx, struct ebml_element_desc * ancestor, void * data)
{
struct list_node * item;
item = ne_alloc(sizeof(*item));
item->previous = ctx->ancestor;
item->node = ancestor;
item->data = data;
ctx->ancestor = item;
}
static void
ne_ctx_pop(nestegg * ctx)
{
struct list_node * item;
item = ctx->ancestor;
ctx->ancestor = item->previous;
free(item);
}
static int
ne_ctx_save(nestegg * ctx, struct saved_state * s)
{
s->stream_offset = ne_io_tell(ctx->io);
if (s->stream_offset < 0)
return -1;
s->ancestor = ctx->ancestor;
s->last_id = ctx->last_id;
s->last_size = ctx->last_size;
s->last_valid = ctx->last_valid;
return 0;
}
static int
ne_ctx_restore(nestegg * ctx, struct saved_state * s)
{
int r;
r = ne_io_seek(ctx->io, s->stream_offset, NESTEGG_SEEK_SET);
if (r != 0)
return -1;
ctx->ancestor = s->ancestor;
ctx->last_id = s->last_id;
ctx->last_size = s->last_size;
ctx->last_valid = s->last_valid;
return 0;
}
static int
ne_peek_element(nestegg * ctx, uint64_t * id, uint64_t * size)
{
int r;
if (ctx->last_valid) {
if (id)
*id = ctx->last_id;
if (size)
*size = ctx->last_size;
return 1;
}
r = ne_read_id(ctx->io, &ctx->last_id, NULL);
if (r != 1)
return r;
r = ne_read_vint(ctx->io, &ctx->last_size, NULL);
if (r != 1)
return r;
if (id)
*id = ctx->last_id;
if (size)
*size = ctx->last_size;
ctx->last_valid = 1;
return 1;
}
static int
ne_read_element(nestegg * ctx, uint64_t * id, uint64_t * size)
{
int r;
r = ne_peek_element(ctx, id, size);
if (r != 1)
return r;
ctx->last_valid = 0;
return 1;
}
static void
ne_read_master(nestegg * ctx, struct ebml_element_desc * desc)
{
struct ebml_list * list;
struct ebml_list_node * node, * oldtail;
assert(desc->type == TYPE_MASTER && desc->flags & DESC_FLAG_MULTI);
ctx->log(ctx, NESTEGG_LOG_DEBUG, "multi master element %llx (%s)",
desc->id, desc->name);
list = (struct ebml_list *) (ctx->ancestor->data + desc->offset);
node = ne_pool_alloc(sizeof(*node), ctx->alloc_pool);
node->id = desc->id;
node->data = ne_pool_alloc(desc->size, ctx->alloc_pool);
oldtail = list->tail;
if (oldtail)
oldtail->next = node;
list->tail = node;
if (!list->head)
list->head = node;
ctx->log(ctx, NESTEGG_LOG_DEBUG, " -> using data %p", node->data);
ne_ctx_push(ctx, desc->children, node->data);
}
static void
ne_read_single_master(nestegg * ctx, struct ebml_element_desc * desc)
{
assert(desc->type == TYPE_MASTER && !(desc->flags & DESC_FLAG_MULTI));
ctx->log(ctx, NESTEGG_LOG_DEBUG, "single master element %llx (%s)",
desc->id, desc->name);
ctx->log(ctx, NESTEGG_LOG_DEBUG, " -> using data %p (%u)",
ctx->ancestor->data + desc->offset, desc->offset);
ne_ctx_push(ctx, desc->children, ctx->ancestor->data + desc->offset);
}
static int
ne_read_simple(nestegg * ctx, struct ebml_element_desc * desc, size_t length)
{
struct ebml_type * storage;
int r = 0;
storage = (struct ebml_type *) (ctx->ancestor->data + desc->offset);
if (storage->read) {
ctx->log(ctx, NESTEGG_LOG_DEBUG, "element %llx (%s) already read, skipping",
desc->id, desc->name);
return 0;
}
storage->type = desc->type;
ctx->log(ctx, NESTEGG_LOG_DEBUG, "element %llx (%s) -> %p (%u)",
desc->id, desc->name, storage, desc->offset);
switch (desc->type) {
case TYPE_UINT:
r = ne_read_uint(ctx->io, &storage->v.u, length);
break;
case TYPE_FLOAT:
r = ne_read_float(ctx->io, &storage->v.f, length);
break;
case TYPE_INT:
r = ne_read_int(ctx->io, &storage->v.i, length);
break;
case TYPE_STRING:
r = ne_read_string(ctx, &storage->v.s, length);
break;
case TYPE_BINARY:
r = ne_read_binary(ctx, &storage->v.b, length);
break;
case TYPE_MASTER:
case TYPE_UNKNOWN:
assert(0);
break;
}
if (r == 1)
storage->read = 1;
return r;
}
static int
ne_parse(nestegg * ctx, struct ebml_element_desc * top_level, int64_t max_offset)
{
int r;
int64_t * data_offset;
uint64_t id, size, peeked_id;
struct ebml_element_desc * element;
if (!ctx->ancestor)
return -1;
for (;;) {
if (max_offset > 0 && ne_io_tell(ctx->io) >= max_offset) {
/* Reached end of offset allowed for parsing - return gracefully */
r = 1;
break;
}
r = ne_peek_element(ctx, &id, &size);
if (r != 1)
break;
peeked_id = id;
element = ne_find_element(id, ctx->ancestor->node);
if (element) {
if (element->flags & DESC_FLAG_SUSPEND) {
assert(element->type == TYPE_BINARY);
ctx->log(ctx, NESTEGG_LOG_DEBUG, "suspend parse at %llx", id);
r = 1;
break;
}
r = ne_read_element(ctx, &id, &size);
if (r != 1)
break;
assert(id == peeked_id);
if (element->flags & DESC_FLAG_OFFSET) {
data_offset = (int64_t *) (ctx->ancestor->data + element->data_offset);
*data_offset = ne_io_tell(ctx->io);
if (*data_offset < 0) {
r = -1;
break;
}
}
if (element->type == TYPE_MASTER) {
if (element->flags & DESC_FLAG_MULTI)
ne_read_master(ctx, element);
else
ne_read_single_master(ctx, element);
continue;
} else {
r = ne_read_simple(ctx, element, (size_t)size);
if (r < 0)
break;
}
} else if (ne_is_ancestor_element(id, ctx->ancestor->previous)) {
ctx->log(ctx, NESTEGG_LOG_DEBUG, "parent element %llx", id);
if (top_level && ctx->ancestor->node == top_level) {
ctx->log(ctx, NESTEGG_LOG_DEBUG, "*** parse about to back up past top_level");
r = 1;
break;
}
ne_ctx_pop(ctx);
} else {
r = ne_read_element(ctx, &id, &size);
if (r != 1)
break;
if (id != ID_VOID && id != ID_CRC32)
ctx->log(ctx, NESTEGG_LOG_DEBUG, "unknown element %llx", id);
r = ne_io_read_skip(ctx->io, (size_t)size);
if (r != 1)
break;
}
}
if (r != 1)
while (ctx->ancestor)
ne_ctx_pop(ctx);
return r;
}
static uint64_t
ne_xiph_lace_value(unsigned char ** np)
{
uint64_t lace;
uint64_t value;
unsigned char * p = *np;
lace = *p++;
value = lace;
while (lace == 255) {
lace = *p++;
value += lace;
}
*np = p;
return value;
}
static int
ne_read_xiph_lace_value(nestegg_io * io, uint64_t * value, size_t * consumed)
{
int r;
uint64_t lace;
r = ne_read_uint(io, &lace, 1);
if (r != 1)
return r;
*consumed += 1;
*value = lace;
while (lace == 255) {
r = ne_read_uint(io, &lace, 1);
if (r != 1)
return r;
*consumed += 1;
*value += lace;
}
return 1;
}
static int
ne_read_xiph_lacing(nestegg_io * io, size_t block, size_t * read, uint64_t n, uint64_t * sizes)
{
int r;
size_t i = 0;
uint64_t sum = 0;
while (--n) {
r = ne_read_xiph_lace_value(io, &sizes[i], read);
if (r != 1)
return r;
sum += sizes[i];
i += 1;
}
if (*read + sum > block)
return -1;
/* Last frame is the remainder of the block. */
sizes[i] = block - *read - sum;
return 1;
}
static int
ne_read_ebml_lacing(nestegg_io * io, size_t block, size_t * read, uint64_t n, uint64_t * sizes)
{
int r;
uint64_t lace, sum, length;
int64_t slace;
size_t i = 0;
r = ne_read_vint(io, &lace, &length);
if (r != 1)
return r;
assert(length <= 8);
*read += (size_t)length;
sizes[i] = lace;
sum = sizes[i];
i += 1;
n -= 1;
while (--n) {
r = ne_read_svint(io, &slace, &length);
if (r != 1)
return r;
assert(length <= 8);
*read += (size_t)length;
sizes[i] = sizes[i - 1] + slace;
sum += sizes[i];
i += 1;
}
if (*read + sum > block)
return -1;
/* Last frame is the remainder of the block. */
sizes[i] = block - *read - sum;
return 1;
}
static uint64_t
ne_get_timecode_scale(nestegg * ctx)
{
uint64_t scale;
if (ne_get_uint(ctx->segment.info.timecode_scale, &scale) != 0)
scale = 1000000;
return scale;
}
static int
ne_map_track_number_to_index(nestegg * ctx,
unsigned int track_number,
unsigned int * track_index)
{
struct ebml_list_node * node;
struct track_entry * t_entry;
uint64_t t_number = 0;
if (!track_index)
return -1;
*track_index = 0;
if (track_number == 0)
return -1;
node = ctx->segment.tracks.track_entry.head;
while (node) {
assert(node->id == ID_TRACK_ENTRY);
t_entry = node->data;
if (ne_get_uint(t_entry->number, &t_number) != 0)
return -1;
if (t_number == track_number)
return 0;
*track_index += 1;
node = node->next;
}
return -1;
}
static struct track_entry *
ne_find_track_entry(nestegg * ctx, unsigned int track)
{
struct ebml_list_node * node;
unsigned int tracks = 0;
node = ctx->segment.tracks.track_entry.head;
while (node) {
assert(node->id == ID_TRACK_ENTRY);
if (track == tracks)
return node->data;
tracks += 1;
node = node->next;
}
return NULL;
}
static int
ne_read_block(nestegg * ctx, uint64_t block_id, uint64_t block_size, nestegg_packet ** data)
{
int r;
int64_t timecode, abs_timecode;
nestegg_packet * pkt;
struct cluster * cluster;
struct frame * f, * last;
struct track_entry * entry;
const int track_scale = 1;
uint64_t track_number, length, frame_sizes[256], cluster_tc, flags, frames, tc_scale, total;
unsigned int i, lacing, track;
size_t consumed = 0;
*data = NULL;
if (block_size > LIMIT_BLOCK)
return -1;
r = ne_read_vint(ctx->io, &track_number, &length);
if (r != 1)
return r;
if (track_number == 0 || (unsigned int)track_number != track_number)
return -1;
assert(length <= 8);
consumed += (size_t)length;
r = ne_read_int(ctx->io, &timecode, 2);
if (r != 1)
return r;
consumed += 2;
r = ne_read_uint(ctx->io, &flags, 1);
if (r != 1)
return r;
consumed += 1;
frames = 0;
/* Flags are different between Block and SimpleBlock, but lacing is
encoded the same way. */
lacing = (flags & BLOCK_FLAGS_LACING) >> 1;
switch (lacing) {
case LACING_NONE:
frames = 1;
break;
case LACING_XIPH:
case LACING_FIXED:
case LACING_EBML:
r = ne_read_uint(ctx->io, &frames, 1);
if (r != 1)
return r;
consumed += 1;
frames += 1;
}
if (frames > 256)
return -1;
switch (lacing) {
case LACING_NONE:
frame_sizes[0] = block_size - consumed;
break;
case LACING_XIPH:
if (frames == 1)
return -1;
r = ne_read_xiph_lacing(ctx->io, (size_t)block_size, &consumed, frames, frame_sizes);
if (r != 1)
return r;
break;
case LACING_FIXED:
if ((block_size - consumed) % frames)
return -1;
for (i = 0; i < frames; ++i)
frame_sizes[i] = (block_size - consumed) / frames;
break;
case LACING_EBML:
if (frames == 1)
return -1;
r = ne_read_ebml_lacing(ctx->io, (size_t)block_size, &consumed, frames, frame_sizes);
if (r != 1)
return r;
break;
}
/* Sanity check unlaced frame sizes against total block size. */
total = consumed;
for (i = 0; i < frames; ++i)
total += frame_sizes[i];
if (total > block_size)
return -1;
if (ne_map_track_number_to_index(ctx, (unsigned int)track_number, &track) != 0)
return -1;
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
tc_scale = ne_get_timecode_scale(ctx);
assert(ctx->segment.cluster.tail->id == ID_CLUSTER);
cluster = ctx->segment.cluster.tail->data;
if (ne_get_uint(cluster->timecode, &cluster_tc) != 0)
return -1;
abs_timecode = timecode + cluster_tc;
if (abs_timecode < 0)
return -1;
pkt = ne_alloc(sizeof(*pkt));
pkt->track = track;
pkt->timecode = abs_timecode * tc_scale * track_scale;
ctx->log(ctx, NESTEGG_LOG_DEBUG, "%sblock t %lld pts %f f %llx frames: %llu",
block_id == ID_BLOCK ? "" : "simple", pkt->track, pkt->timecode / 1e9, flags, frames);
last = NULL;
for (i = 0; i < frames; ++i) {
if (frame_sizes[i] > LIMIT_FRAME) {
nestegg_free_packet(pkt);
return -1;
}
f = ne_alloc(sizeof(*f));
f->length = (size_t)frame_sizes[i];
f->data = ne_alloc(f->length);
r = ne_io_read(ctx->io, f->data, f->length);
if (r != 1) {
free(f->data);
free(f);
nestegg_free_packet(pkt);
return -1;
}
if (!last)
pkt->frame = f;
else
last->next = f;
last = f;
}
*data = pkt;
return 1;
}
static int
ne_read_discard_padding(nestegg * ctx, nestegg_packet * pkt)
{
int r;
uint64_t id, size;
struct ebml_element_desc * element;
struct ebml_type * storage;
r = ne_peek_element(ctx, &id, &size);
if (r != 1)
return r;
if (id != ID_DISCARD_PADDING)
return 1;
element = ne_find_element(id, ctx->ancestor->node);
if (!element)
return 1;
assert((size_t)size == size);
r = ne_read_simple(ctx, element, (size_t)size);
if (r != 1)
return r;
storage = (struct ebml_type *) (ctx->ancestor->data + element->offset);
pkt->discard_padding = storage->v.i;
return 1;
}
static uint64_t
ne_buf_read_id(unsigned char const * p, size_t length)
{
uint64_t id = 0;
while (length--) {
id <<= 8;
id |= *p++;
}
return id;
}
static struct seek *
ne_find_seek_for_id(struct ebml_list_node * seek_head, uint64_t id)
{
struct ebml_list * head;
struct ebml_list_node * seek;
struct ebml_binary binary_id;
struct seek * s;
while (seek_head) {
assert(seek_head->id == ID_SEEK_HEAD);
head = seek_head->data;
seek = head->head;
while (seek) {
assert(seek->id == ID_SEEK);
s = seek->data;
if (ne_get_binary(s->id, &binary_id) == 0 &&
ne_buf_read_id(binary_id.data, binary_id.length) == id)
return s;
seek = seek->next;
}
seek_head = seek_head->next;
}
return NULL;
}
static struct cue_track_positions *
ne_find_cue_position_for_track(nestegg * ctx, struct ebml_list_node * node, unsigned int track)
{
struct cue_track_positions * pos = NULL;
unsigned int track_number;
unsigned int t;
while (node) {
assert(node->id == ID_CUE_TRACK_POSITIONS);
pos = node->data;
if (ne_get_uint32(pos->track, &track_number) != 0)
return NULL;
if (ne_map_track_number_to_index(ctx, track_number, &t) != 0)
return NULL;
if (t == track)
return pos;
node = node->next;
}
return NULL;
}
static struct cue_point *
ne_find_cue_point_for_tstamp(nestegg * ctx, struct ebml_list_node * cue_point, unsigned int track, uint64_t scale, uint64_t tstamp)
{
uint64_t time;
struct cue_point * c, * prev = NULL;
while (cue_point) {
assert(cue_point->id == ID_CUE_POINT);
c = cue_point->data;
if (!prev)
prev = c;
if (ne_get_uint(c->time, &time) == 0 && time * scale > tstamp)
break;
if (ne_find_cue_position_for_track(ctx, c->cue_track_positions.head, track) != NULL)
prev = c;
cue_point = cue_point->next;
}
return prev;
}
static int
ne_is_suspend_element(uint64_t id)
{
if (id == ID_SIMPLE_BLOCK || id == ID_BLOCK)
return 1;
return 0;
}
static void
ne_null_log_callback(nestegg * ctx, unsigned int severity, char const * fmt, ...)
{
if (ctx && severity && fmt)
return;
}
static int
ne_init_cue_points(nestegg * ctx, int64_t max_offset)
{
int r;
struct ebml_list_node * node = ctx->segment.cues.cue_point.head;
struct seek * found;
uint64_t seek_pos, id;
struct saved_state state;
/* If there are no cues loaded, check for cues element in the seek head
and load it. */
if (!node) {
found = ne_find_seek_for_id(ctx->segment.seek_head.head, ID_CUES);
if (!found)
return -1;
if (ne_get_uint(found->position, &seek_pos) != 0)
return -1;
/* Save old parser state. */
r = ne_ctx_save(ctx, &state);
if (r != 0)
return -1;
/* Seek and set up parser state for segment-level element (Cues). */
r = ne_io_seek(ctx->io, ctx->segment_offset + seek_pos, NESTEGG_SEEK_SET);
if (r != 0)
return -1;
ctx->last_valid = 0;
r = ne_read_element(ctx, &id, NULL);
if (r != 1)
return -1;
if (id != ID_CUES)
return -1;
ctx->ancestor = NULL;
ne_ctx_push(ctx, ne_top_level_elements, ctx);
ne_ctx_push(ctx, ne_segment_elements, &ctx->segment);
ne_ctx_push(ctx, ne_cues_elements, &ctx->segment.cues);
/* parser will run until end of cues element. */
ctx->log(ctx, NESTEGG_LOG_DEBUG, "seek: parsing cue elements");
r = ne_parse(ctx, ne_cues_elements, max_offset);
while (ctx->ancestor)
ne_ctx_pop(ctx);
/* Reset parser state to original state and seek back to old position. */
if (ne_ctx_restore(ctx, &state) != 0)
return -1;
if (r < 0)
return -1;
node = ctx->segment.cues.cue_point.head;
if (!node)
return -1;
}
return 0;
}
/* Three functions that implement the nestegg_io interface, operating on a
* sniff_buffer. */
struct sniff_buffer {
unsigned char const * buffer;
size_t length;
int64_t offset;
};
static int
ne_buffer_read(void * buffer, size_t length, void * user_data)
{
struct sniff_buffer * sb = user_data;
int rv = 1;
size_t available = sb->length - (size_t)sb->offset;
if (available < length)
return 0;
memcpy(buffer, sb->buffer + sb->offset, length);
sb->offset += length;
return rv;
}
static int
ne_buffer_seek(int64_t offset, int whence, void * user_data)
{
struct sniff_buffer * sb = user_data;
int64_t o = sb->offset;
switch(whence) {
case NESTEGG_SEEK_SET:
o = offset;
break;
case NESTEGG_SEEK_CUR:
o += offset;
break;
case NESTEGG_SEEK_END:
o = sb->length + offset;
break;
}
if (o < 0 || o > (int64_t) sb->length)
return -1;
sb->offset = o;
return 0;
}
static int64_t
ne_buffer_tell(void * user_data)
{
struct sniff_buffer * sb = user_data;
return sb->offset;
}
static int
ne_match_webm(nestegg_io io, int64_t max_offset)
{
int r;
uint64_t id;
char * doctype;
nestegg * ctx;
if (!(io.read && io.seek && io.tell))
return -1;
ctx = ne_alloc(sizeof(*ctx));
ctx->io = ne_alloc(sizeof(*ctx->io));
*ctx->io = io;
ctx->alloc_pool = ne_pool_init();
ctx->log = ne_null_log_callback;
r = ne_peek_element(ctx, &id, NULL);
if (r != 1) {
nestegg_destroy(ctx);
return 0;
}
if (id != ID_EBML) {
nestegg_destroy(ctx);
return 0;
}
ne_ctx_push(ctx, ne_top_level_elements, ctx);
/* we don't check the return value of ne_parse, that might fail because
* max_offset is not on a valid element end point. We only want to check
* the EBML ID and that the doctype is "webm". */
ne_parse(ctx, NULL, max_offset);
if (ne_get_string(ctx->ebml.doctype, &doctype) != 0 ||
strcmp(doctype, "webm") != 0) {
nestegg_destroy(ctx);
return 0;
}
nestegg_destroy(ctx);
return 1;
}
int
nestegg_init(nestegg ** context, nestegg_io io, nestegg_log callback, int64_t max_offset)
{
int r;
uint64_t id, version, docversion;
struct ebml_list_node * track;
char * doctype;
nestegg * ctx;
if (!(io.read && io.seek && io.tell))
return -1;
ctx = ne_alloc(sizeof(*ctx));
ctx->io = ne_alloc(sizeof(*ctx->io));
*ctx->io = io;
ctx->log = callback;
ctx->alloc_pool = ne_pool_init();
if (!ctx->log)
ctx->log = ne_null_log_callback;
r = ne_peek_element(ctx, &id, NULL);
if (r != 1) {
nestegg_destroy(ctx);
return -1;
}
if (id != ID_EBML) {
nestegg_destroy(ctx);
return -1;
}
ctx->log(ctx, NESTEGG_LOG_DEBUG, "ctx %p", ctx);
ne_ctx_push(ctx, ne_top_level_elements, ctx);
r = ne_parse(ctx, NULL, max_offset);
if (r != 1) {
nestegg_destroy(ctx);
return -1;
}
if (ne_get_uint(ctx->ebml.ebml_read_version, &version) != 0)
version = 1;
if (version != 1) {
nestegg_destroy(ctx);
return -1;
}
if (ne_get_string(ctx->ebml.doctype, &doctype) != 0)
doctype = "matroska";
if (strcmp(doctype, "webm") != 0) {
nestegg_destroy(ctx);
return -1;
}
if (ne_get_uint(ctx->ebml.doctype_read_version, &docversion) != 0)
docversion = 1;
if (docversion < 1 || docversion > 2) {
nestegg_destroy(ctx);
return -1;
}
if (!ctx->segment.tracks.track_entry.head) {
nestegg_destroy(ctx);
return -1;
}
track = ctx->segment.tracks.track_entry.head;
ctx->track_count = 0;
while (track) {
ctx->track_count += 1;
track = track->next;
}
*context = ctx;
return 0;
}
void
nestegg_destroy(nestegg * ctx)
{
while (ctx->ancestor)
ne_ctx_pop(ctx);
ne_pool_destroy(ctx->alloc_pool);
free(ctx->io);
free(ctx);
}
int
nestegg_duration(nestegg * ctx, uint64_t * duration)
{
uint64_t tc_scale;
double unscaled_duration;
if (ne_get_float(ctx->segment.info.duration, &unscaled_duration) != 0)
return -1;
tc_scale = ne_get_timecode_scale(ctx);
*duration = (uint64_t) (unscaled_duration * tc_scale);
return 0;
}
int
nestegg_tstamp_scale(nestegg * ctx, uint64_t * scale)
{
*scale = ne_get_timecode_scale(ctx);
return 0;
}
int
nestegg_track_count(nestegg * ctx, unsigned int * tracks)
{
*tracks = ctx->track_count;
return 0;
}
int
nestegg_get_cue_point(nestegg * ctx, unsigned int cluster_num, int64_t max_offset,
int64_t * start_pos, int64_t * end_pos, uint64_t * tstamp)
{
int range_obtained = 0;
unsigned int cluster_count = 0;
struct cue_point * cue_point;
struct cue_track_positions * pos;
uint64_t seek_pos, track_number, tc_scale, time;
struct ebml_list_node * cues_node = ctx->segment.cues.cue_point.head;
struct ebml_list_node * cue_pos_node = NULL;
unsigned int track = 0, track_count = 0, track_index;
if (!start_pos || !end_pos || !tstamp)
return -1;
/* Initialise return values */
*start_pos = -1;
*end_pos = -1;
*tstamp = 0;
if (!cues_node) {
ne_init_cue_points(ctx, max_offset);
cues_node = ctx->segment.cues.cue_point.head;
/* Verify cues have been added to context. */
if (!cues_node)
return -1;
}
nestegg_track_count(ctx, &track_count);
tc_scale = ne_get_timecode_scale(ctx);
while (cues_node && !range_obtained) {
assert(cues_node->id == ID_CUE_POINT);
cue_point = cues_node->data;
cue_pos_node = cue_point->cue_track_positions.head;
while (cue_pos_node) {
assert(cue_pos_node->id == ID_CUE_TRACK_POSITIONS);
pos = cue_pos_node->data;
for (track = 0; track < track_count; track++) {
if (ne_get_uint(pos->track, &track_number) != 0)
return -1;
if (ne_map_track_number_to_index(ctx, (unsigned int)track_number, &track_index) != 0)
return -1;
if (track_index == track) {
if (ne_get_uint(pos->cluster_position, &seek_pos) != 0)
return -1;
if (cluster_count == cluster_num) {
*start_pos = ctx->segment_offset+seek_pos;
if (ne_get_uint(cue_point->time, &time) != 0)
return -1;
*tstamp = time * tc_scale;
} else if (cluster_count == cluster_num+1) {
*end_pos = (ctx->segment_offset+seek_pos)-1;
range_obtained = 1;
break;
}
cluster_count++;
}
}
cue_pos_node = cue_pos_node->next;
}
cues_node = cues_node->next;
}
return 0;
}
int
nestegg_offset_seek(nestegg * ctx, uint64_t offset)
{
int r;
/* Seek and set up parser state for segment-level element (Cluster). */
r = ne_io_seek(ctx->io, offset, NESTEGG_SEEK_SET);
if (r != 0)
return -1;
ctx->last_valid = 0;
while (ctx->ancestor)
ne_ctx_pop(ctx);
ne_ctx_push(ctx, ne_top_level_elements, ctx);
ne_ctx_push(ctx, ne_segment_elements, &ctx->segment);
return 0;
}
int
nestegg_track_seek(nestegg * ctx, unsigned int track, uint64_t tstamp)
{
int r;
struct cue_point * cue_point;
struct cue_track_positions * pos;
uint64_t seek_pos, tc_scale;
/* If there are no cues loaded, check for cues element in the seek head
and load it. */
if (!ctx->segment.cues.cue_point.head) {
r = ne_init_cue_points(ctx, -1);
if (r != 0)
return -1;
}
tc_scale = ne_get_timecode_scale(ctx);
cue_point = ne_find_cue_point_for_tstamp(ctx, ctx->segment.cues.cue_point.head,
track, tc_scale, tstamp);
if (!cue_point)
return -1;
pos = ne_find_cue_position_for_track(ctx, cue_point->cue_track_positions.head, track);
if (pos == NULL)
return -1;
if (ne_get_uint(pos->cluster_position, &seek_pos) != 0)
return -1;
/* Seek and set up parser state for segment-level element (Cluster). */
r = nestegg_offset_seek(ctx, ctx->segment_offset + seek_pos);
ctx->log(ctx, NESTEGG_LOG_DEBUG, "seek: parsing cluster elements");
r = ne_parse(ctx, NULL, -1);
if (r != 1)
return -1;
if (!ne_is_suspend_element(ctx->last_id))
return -1;
return 0;
}
int
nestegg_track_type(nestegg * ctx, unsigned int track)
{
struct track_entry * entry;
uint64_t type;
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
if (ne_get_uint(entry->type, &type) != 0)
return -1;
if (type & TRACK_TYPE_VIDEO)
return NESTEGG_TRACK_VIDEO;
if (type & TRACK_TYPE_AUDIO)
return NESTEGG_TRACK_AUDIO;
return -1;
}
int
nestegg_track_codec_id(nestegg * ctx, unsigned int track)
{
char * codec_id;
struct track_entry * entry;
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
if (ne_get_string(entry->codec_id, &codec_id) != 0)
return -1;
if (strcmp(codec_id, TRACK_ID_VP8) == 0)
return NESTEGG_CODEC_VP8;
if (strcmp(codec_id, TRACK_ID_VP9) == 0)
return NESTEGG_CODEC_VP9;
if (strcmp(codec_id, TRACK_ID_VORBIS) == 0)
return NESTEGG_CODEC_VORBIS;
if (strcmp(codec_id, TRACK_ID_OPUS) == 0)
return NESTEGG_CODEC_OPUS;
return -1;
}
int
nestegg_track_codec_data_count(nestegg * ctx, unsigned int track,
unsigned int * count)
{
struct track_entry * entry;
struct ebml_binary codec_private;
unsigned char * p;
*count = 0;
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
if (nestegg_track_codec_id(ctx, track) != NESTEGG_CODEC_VORBIS)
return -1;
if (ne_get_binary(entry->codec_private, &codec_private) != 0)
return -1;
if (codec_private.length < 1)
return -1;
p = codec_private.data;
*count = *p + 1;
if (*count > 3)
return -1;
return 0;
}
int
nestegg_track_codec_data(nestegg * ctx, unsigned int track, unsigned int item,
unsigned char ** data, size_t * length)
{
struct track_entry * entry;
struct ebml_binary codec_private;
uint64_t sizes[3], total;
unsigned char * p;
unsigned int count, i;
*data = NULL;
*length = 0;
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
if (nestegg_track_codec_id(ctx, track) != NESTEGG_CODEC_VORBIS
&& nestegg_track_codec_id(ctx, track) != NESTEGG_CODEC_OPUS)
return -1;
if (ne_get_binary(entry->codec_private, &codec_private) != 0)
return -1;
if (nestegg_track_codec_id(ctx, track) == NESTEGG_CODEC_VORBIS) {
p = codec_private.data;
count = *p++ + 1;
if (count > 3)
return -1;
i = 0;
total = 0;
while (--count) {
sizes[i] = ne_xiph_lace_value(&p);
total += sizes[i];
i += 1;
}
sizes[i] = codec_private.length - total - (p - codec_private.data);
for (i = 0; i < item; ++i) {
if (sizes[i] > LIMIT_FRAME)
return -1;
p += sizes[i];
}
*data = p;
*length = (size_t)sizes[item];
} else {
*data = codec_private.data;
*length = codec_private.length;
}
return 0;
}
int
nestegg_track_video_params(nestegg * ctx, unsigned int track,
nestegg_video_params * params)
{
struct track_entry * entry;
unsigned int value;
memset(params, 0, sizeof(*params));
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
if (nestegg_track_type(ctx, track) != NESTEGG_TRACK_VIDEO)
return -1;
value = 0;
ne_get_uint32(entry->video.stereo_mode, &value);
if (value <= NESTEGG_VIDEO_STEREO_TOP_BOTTOM ||
value == NESTEGG_VIDEO_STEREO_RIGHT_LEFT)
params->stereo_mode = value;
if (ne_get_uint32(entry->video.pixel_width, &value) != 0)
return -1;
params->width = value;
if (ne_get_uint32(entry->video.pixel_height, &value) != 0)
return -1;
params->height = value;
value = 0;
ne_get_uint32(entry->video.pixel_crop_bottom, &value);
params->crop_bottom = value;
value = 0;
ne_get_uint32(entry->video.pixel_crop_top, &value);
params->crop_top = value;
value = 0;
ne_get_uint32(entry->video.pixel_crop_left, &value);
params->crop_left = value;
value = 0;
ne_get_uint32(entry->video.pixel_crop_right, &value);
params->crop_right = value;
value = params->width;
ne_get_uint32(entry->video.display_width, &value);
params->display_width = value;
value = params->height;
ne_get_uint32(entry->video.display_height, &value);
params->display_height = value;
return 0;
}
int
nestegg_track_audio_params(nestegg * ctx, unsigned int track,
nestegg_audio_params * params)
{
struct track_entry * entry;
unsigned int value;
memset(params, 0, sizeof(*params));
entry = ne_find_track_entry(ctx, track);
if (!entry)
return -1;
if (nestegg_track_type(ctx, track) != NESTEGG_TRACK_AUDIO)
return -1;
params->rate = 8000;
ne_get_float(entry->audio.sampling_frequency, ¶ms->rate);
value = 1;
ne_get_uint32(entry->audio.channels, &value);
params->channels = value;
value = 16;
ne_get_uint32(entry->audio.bit_depth, &value);
params->depth = value;
value = 0;
ne_get_uint32(entry->codec_delay, &value);
params->codec_delay = value;
value = 0;
ne_get_uint32(entry->seek_preroll, &value);
params->seek_preroll = value;
return 0;
}
int
nestegg_read_packet(nestegg * ctx, nestegg_packet ** pkt)
{
int r;
uint64_t id, size;
*pkt = NULL;
for (;;) {
r = ne_peek_element(ctx, &id, &size);
if (r != 1)
return r;
/* Any DESC_FLAG_SUSPEND fields must be handled here. */
if (ne_is_suspend_element(id)) {
r = ne_read_element(ctx, &id, &size);
if (r != 1)
return r;
/* The only DESC_FLAG_SUSPEND fields are Blocks and SimpleBlocks, which we
handle directly. */
r = ne_read_block(ctx, id, size, pkt);
if (r != 1)
return r;
r = ne_read_discard_padding(ctx, *pkt);
if (r != 1)
return r;
return r;
}
r = ne_parse(ctx, NULL, -1);
if (r != 1)
return r;
}
return 1;
}
void
nestegg_free_packet(nestegg_packet * pkt)
{
struct frame * frame;
while (pkt->frame) {
frame = pkt->frame;
pkt->frame = frame->next;
free(frame->data);
free(frame);
}
free(pkt);
}
int
nestegg_packet_track(nestegg_packet * pkt, unsigned int * track)
{
*track = (unsigned int)pkt->track;
return 0;
}
int
nestegg_packet_tstamp(nestegg_packet * pkt, uint64_t * tstamp)
{
*tstamp = pkt->timecode;
return 0;
}
int
nestegg_packet_discard_padding(nestegg_packet * pkt, int64_t * discard_padding)
{
*discard_padding = pkt->discard_padding;
return 0;
}
int
nestegg_packet_count(nestegg_packet * pkt, unsigned int * count)
{
struct frame * f = pkt->frame;
*count = 0;
while (f) {
*count += 1;
f = f->next;
}
return 0;
}
int
nestegg_packet_data(nestegg_packet * pkt, unsigned int item,
unsigned char ** data, size_t * length)
{
struct frame * f = pkt->frame;
unsigned int count = 0;
*data = NULL;
*length = 0;
while (f) {
if (count == item) {
*data = f->data;
*length = f->length;
return 0;
}
count += 1;
f = f->next;
}
return -1;
}
int
nestegg_has_cues(nestegg * ctx)
{
return ctx->segment.cues.cue_point.head ||
ne_find_seek_for_id(ctx->segment.seek_head.head, ID_CUES);
}
int
nestegg_sniff(unsigned char const * buffer, size_t length)
{
nestegg_io io;
struct sniff_buffer user_data;
user_data.buffer = buffer;
user_data.length = length;
user_data.offset = 0;
io.read = ne_buffer_read;
io.seek = ne_buffer_seek;
io.tell = ne_buffer_tell;
io.userdata = &user_data;
return ne_match_webm(io, length);
}