ref: c6a1ff223b80f77ae08c4a6fab2e11843c0a2e37
dir: /webmenc.c/
/*
* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webmenc.h"
#include <limits.h>
#include <string.h>
#include "third_party/libmkv/EbmlWriter.h"
#include "third_party/libmkv/EbmlIDs.h"
void Ebml_Write(struct EbmlGlobal *glob,
const void *buffer_in,
unsigned long len) {
(void) fwrite(buffer_in, 1, len, glob->stream);
}
#define WRITE_BUFFER(s) \
for (i = len - 1; i >= 0; i--) { \
x = (char)(*(const s *)buffer_in >> (i * CHAR_BIT)); \
Ebml_Write(glob, &x, 1); \
}
void Ebml_Serialize(struct EbmlGlobal *glob,
const void *buffer_in,
int buffer_size,
unsigned long len) {
char x;
int i;
/* buffer_size:
* 1 - int8_t;
* 2 - int16_t;
* 3 - int32_t;
* 4 - int64_t;
*/
switch (buffer_size) {
case 1:
WRITE_BUFFER(int8_t)
break;
case 2:
WRITE_BUFFER(int16_t)
break;
case 4:
WRITE_BUFFER(int32_t)
break;
case 8:
WRITE_BUFFER(int64_t)
break;
default:
break;
}
}
#undef WRITE_BUFFER
/* Need a fixed size serializer for the track ID. libmkv provides a 64 bit
* one, but not a 32 bit one.
*/
static void Ebml_SerializeUnsigned32(struct EbmlGlobal *glob,
unsigned int class_id,
uint64_t ui) {
const unsigned char sizeSerialized = 4 | 0x80;
Ebml_WriteID(glob, class_id);
Ebml_Serialize(glob, &sizeSerialized, sizeof(sizeSerialized), 1);
Ebml_Serialize(glob, &ui, sizeof(ui), 4);
}
static void Ebml_StartSubElement(struct EbmlGlobal *glob,
EbmlLoc *ebmlLoc,
unsigned int class_id) {
const uint64_t kEbmlUnknownLength = LITERALU64(0x01FFFFFF, 0xFFFFFFFF);
Ebml_WriteID(glob, class_id);
*ebmlLoc = ftello(glob->stream);
Ebml_Serialize(glob, &kEbmlUnknownLength, sizeof(kEbmlUnknownLength), 8);
}
static void Ebml_EndSubElement(struct EbmlGlobal *glob, EbmlLoc *ebmlLoc) {
off_t pos;
uint64_t size;
/* Save the current stream pointer. */
pos = ftello(glob->stream);
/* Calculate the size of this element. */
size = pos - *ebmlLoc - 8;
size |= LITERALU64(0x01000000, 0x00000000);
/* Seek back to the beginning of the element and write the new size. */
fseeko(glob->stream, *ebmlLoc, SEEK_SET);
Ebml_Serialize(glob, &size, sizeof(size), 8);
/* Reset the stream pointer. */
fseeko(glob->stream, pos, SEEK_SET);
}
void write_webm_seek_element(struct EbmlGlobal *ebml,
unsigned int id,
off_t pos) {
uint64_t offset = pos - ebml->position_reference;
EbmlLoc start;
Ebml_StartSubElement(ebml, &start, Seek);
Ebml_SerializeBinary(ebml, SeekID, id);
Ebml_SerializeUnsigned64(ebml, SeekPosition, offset);
Ebml_EndSubElement(ebml, &start);
}
void write_webm_seek_info(struct EbmlGlobal *ebml) {
off_t pos;
EbmlLoc start;
EbmlLoc startInfo;
uint64_t frame_time;
char version_string[64];
/* Save the current stream pointer. */
pos = ftello(ebml->stream);
if (ebml->seek_info_pos)
fseeko(ebml->stream, ebml->seek_info_pos, SEEK_SET);
else
ebml->seek_info_pos = pos;
Ebml_StartSubElement(ebml, &start, SeekHead);
write_webm_seek_element(ebml, Tracks, ebml->track_pos);
write_webm_seek_element(ebml, Cues, ebml->cue_pos);
write_webm_seek_element(ebml, Info, ebml->segment_info_pos);
Ebml_EndSubElement(ebml, &start);
/* Create and write the Segment Info. */
if (ebml->debug) {
strcpy(version_string, "vpxenc");
} else {
strcpy(version_string, "vpxenc ");
strncat(version_string,
vpx_codec_version_str(),
sizeof(version_string) - 1 - strlen(version_string));
}
frame_time = (uint64_t)1000 * ebml->framerate.den
/ ebml->framerate.num;
ebml->segment_info_pos = ftello(ebml->stream);
Ebml_StartSubElement(ebml, &startInfo, Info);
Ebml_SerializeUnsigned(ebml, TimecodeScale, 1000000);
Ebml_SerializeFloat(ebml, Segment_Duration,
(double)(ebml->last_pts_ms + frame_time));
Ebml_SerializeString(ebml, 0x4D80, version_string);
Ebml_SerializeString(ebml, 0x5741, version_string);
Ebml_EndSubElement(ebml, &startInfo);
}
void write_webm_file_header(struct EbmlGlobal *glob,
const vpx_codec_enc_cfg_t *cfg,
const struct vpx_rational *fps,
stereo_format_t stereo_fmt,
unsigned int fourcc) {
EbmlLoc start;
EbmlLoc trackStart;
EbmlLoc videoStart;
unsigned int trackNumber = 1;
uint64_t trackID = 0;
unsigned int pixelWidth = cfg->g_w;
unsigned int pixelHeight = cfg->g_h;
/* Write the EBML header. */
Ebml_StartSubElement(glob, &start, EBML);
Ebml_SerializeUnsigned(glob, EBMLVersion, 1);
Ebml_SerializeUnsigned(glob, EBMLReadVersion, 1);
Ebml_SerializeUnsigned(glob, EBMLMaxIDLength, 4);
Ebml_SerializeUnsigned(glob, EBMLMaxSizeLength, 8);
Ebml_SerializeString(glob, DocType, "webm");
Ebml_SerializeUnsigned(glob, DocTypeVersion, 2);
Ebml_SerializeUnsigned(glob, DocTypeReadVersion, 2);
Ebml_EndSubElement(glob, &start);
/* Open and begin writing the segment element. */
Ebml_StartSubElement(glob, &glob->startSegment, Segment);
glob->position_reference = ftello(glob->stream);
glob->framerate = *fps;
write_webm_seek_info(glob);
/* Open and write the Tracks element. */
glob->track_pos = ftello(glob->stream);
Ebml_StartSubElement(glob, &trackStart, Tracks);
/* Open and write the Track entry. */
Ebml_StartSubElement(glob, &start, TrackEntry);
Ebml_SerializeUnsigned(glob, TrackNumber, trackNumber);
glob->track_id_pos = ftello(glob->stream);
Ebml_SerializeUnsigned32(glob, TrackUID, trackID);
Ebml_SerializeUnsigned(glob, TrackType, 1);
Ebml_SerializeString(glob, CodecID,
fourcc == VP8_FOURCC ? "V_VP8" : "V_VP9");
Ebml_StartSubElement(glob, &videoStart, Video);
Ebml_SerializeUnsigned(glob, PixelWidth, pixelWidth);
Ebml_SerializeUnsigned(glob, PixelHeight, pixelHeight);
Ebml_SerializeUnsigned(glob, StereoMode, stereo_fmt);
Ebml_EndSubElement(glob, &videoStart);
/* Close Track entry. */
Ebml_EndSubElement(glob, &start);
/* Close Tracks element. */
Ebml_EndSubElement(glob, &trackStart);
/* Segment element remains open. */
}
void write_webm_block(struct EbmlGlobal *glob,
const vpx_codec_enc_cfg_t *cfg,
const vpx_codec_cx_pkt_t *pkt) {
unsigned int block_length;
unsigned char track_number;
uint16_t block_timecode = 0;
unsigned char flags;
int64_t pts_ms;
int start_cluster = 0, is_keyframe;
/* Calculate the PTS of this frame in milliseconds. */
pts_ms = pkt->data.frame.pts * 1000
* (uint64_t)cfg->g_timebase.num / (uint64_t)cfg->g_timebase.den;
if (pts_ms <= glob->last_pts_ms)
pts_ms = glob->last_pts_ms + 1;
glob->last_pts_ms = pts_ms;
/* Calculate the relative time of this block. */
if (pts_ms - glob->cluster_timecode > SHRT_MAX)
start_cluster = 1;
else
block_timecode = (uint16_t)pts_ms - glob->cluster_timecode;
is_keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY);
if (start_cluster || is_keyframe) {
if (glob->cluster_open)
Ebml_EndSubElement(glob, &glob->startCluster);
/* Open the new cluster. */
block_timecode = 0;
glob->cluster_open = 1;
glob->cluster_timecode = (uint32_t)pts_ms;
glob->cluster_pos = ftello(glob->stream);
Ebml_StartSubElement(glob, &glob->startCluster, Cluster);
Ebml_SerializeUnsigned(glob, Timecode, glob->cluster_timecode);
/* Save a cue point if this is a keyframe. */
if (is_keyframe) {
struct cue_entry *cue, *new_cue_list;
new_cue_list = realloc(glob->cue_list,
(glob->cues + 1) * sizeof(struct cue_entry));
if (new_cue_list)
glob->cue_list = new_cue_list;
else
fatal("Failed to realloc cue list.");
cue = &glob->cue_list[glob->cues];
cue->time = glob->cluster_timecode;
cue->loc = glob->cluster_pos;
glob->cues++;
}
}
/* Write the Simple Block. */
Ebml_WriteID(glob, SimpleBlock);
block_length = (unsigned int)pkt->data.frame.sz + 4;
block_length |= 0x10000000;
Ebml_Serialize(glob, &block_length, sizeof(block_length), 4);
track_number = 1;
track_number |= 0x80;
Ebml_Write(glob, &track_number, 1);
Ebml_Serialize(glob, &block_timecode, sizeof(block_timecode), 2);
flags = 0;
if (is_keyframe)
flags |= 0x80;
if (pkt->data.frame.flags & VPX_FRAME_IS_INVISIBLE)
flags |= 0x08;
Ebml_Write(glob, &flags, 1);
Ebml_Write(glob, pkt->data.frame.buf, (unsigned int)pkt->data.frame.sz);
}
void write_webm_file_footer(struct EbmlGlobal *glob, int hash) {
EbmlLoc start_cues;
EbmlLoc start_cue_point;
EbmlLoc start_cue_tracks;
unsigned int i;
if (glob->cluster_open)
Ebml_EndSubElement(glob, &glob->startCluster);
glob->cue_pos = ftello(glob->stream);
Ebml_StartSubElement(glob, &start_cues, Cues);
for (i = 0; i < glob->cues; i++) {
struct cue_entry *cue = &glob->cue_list[i];
Ebml_StartSubElement(glob, &start_cue_point, CuePoint);
Ebml_SerializeUnsigned(glob, CueTime, cue->time);
Ebml_StartSubElement(glob, &start_cue_tracks, CueTrackPositions);
Ebml_SerializeUnsigned(glob, CueTrack, 1);
Ebml_SerializeUnsigned64(glob, CueClusterPosition,
cue->loc - glob->position_reference);
Ebml_EndSubElement(glob, &start_cue_tracks);
Ebml_EndSubElement(glob, &start_cue_point);
}
Ebml_EndSubElement(glob, &start_cues);
/* Close the Segment. */
Ebml_EndSubElement(glob, &glob->startSegment);
/* Patch up the seek info block. */
write_webm_seek_info(glob);
/* Patch up the track id. */
fseeko(glob->stream, glob->track_id_pos, SEEK_SET);
Ebml_SerializeUnsigned32(glob, TrackUID, glob->debug ? 0xDEADBEEF : hash);
fseeko(glob->stream, 0, SEEK_END);
}