ref: 46d092ae6ac62284e5bdde4d0808aca4ab7410a9
parent: eb4a8f6d076225fc5e75eed585535eccca1b3ace
author: Ronald S. Bultje <rsbultje@gmail.com>
date: Sat Nov 16 09:45:24 EST 2019
Add demuxer probing This allows auto-detection between section5 and annexb files, which share the same extension.
--- a/tools/input/annexb.c
+++ b/tools/input/annexb.c
@@ -1,6 +1,7 @@
/*
* Copyright © 2018, VideoLAN and dav1d authors
* Copyright © 2018, Two Orioles, LLC
+ * Copyright © 2019, James Almer <jamrial@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -32,9 +33,92 @@
#include <stdlib.h>
#include <string.h>
+#include "common/intops.h"
+
+#include "dav1d/headers.h"
+
#include "input/demuxer.h"
#include "input/parse.h"
+// these functions are based on an implementation from FFmpeg, and relicensed
+// with author's permission
+
+#define PROBE_SIZE 1024
+
+static int annexb_probe(const uint8_t *data) {+ int ret, cnt = 0;
+
+ size_t temporal_unit_size;
+ ret = leb(data + cnt, PROBE_SIZE - cnt, &temporal_unit_size);
+ if (ret < 0)
+ return 0;
+ cnt += ret;
+
+ size_t frame_unit_size;
+ ret = leb(data + cnt, PROBE_SIZE - cnt, &frame_unit_size);
+ if (ret < 0 || ((uint64_t)frame_unit_size + ret) > temporal_unit_size)
+ return 0;
+ cnt += ret;
+
+ temporal_unit_size -= ret;
+
+ size_t obu_unit_size;
+ ret = leb(data + cnt, PROBE_SIZE - cnt, &obu_unit_size);
+ if (ret < 0 || ((uint64_t)obu_unit_size + ret) >= frame_unit_size)
+ return 0;
+ cnt += ret;
+
+ temporal_unit_size -= obu_unit_size + ret;
+ frame_unit_size -= obu_unit_size + ret;
+
+ // Check that the first OBU is a Temporal Delimiter.
+ size_t obu_size;
+ enum Dav1dObuType type;
+ ret = parse_obu_header(data + cnt, imin(PROBE_SIZE - cnt, (int) obu_unit_size),
+ &obu_size, &type, 1);
+ if (ret < 0 || type != DAV1D_OBU_TD || obu_size > 0)
+ return 0;
+ cnt += obu_unit_size;
+
+ // look for first frame and accompanying sequence header
+ int seq = 0;
+ while (cnt < PROBE_SIZE) {+ ret = leb(data + cnt, PROBE_SIZE - cnt, &obu_unit_size);
+ if (ret < 0 || ((uint64_t)obu_unit_size + ret) > frame_unit_size)
+ return 0;
+ cnt += ret;
+ temporal_unit_size -= ret;
+ frame_unit_size -= ret;
+
+ ret = parse_obu_header(data + cnt, imin(PROBE_SIZE - cnt, (int) obu_unit_size),
+ &obu_size, &type, 1);
+ if (ret < 0)
+ return 0;
+ cnt += obu_unit_size;
+
+ switch (type) {+ case DAV1D_OBU_SEQ_HDR:
+ seq = 1;
+ break;
+ case DAV1D_OBU_FRAME:
+ case DAV1D_OBU_FRAME_HDR:
+ return seq;
+ case DAV1D_OBU_TD:
+ case DAV1D_OBU_TILE_GRP:
+ return 0;
+ default:
+ break;
+ }
+
+ temporal_unit_size -= obu_unit_size;
+ frame_unit_size -= obu_unit_size;
+ if (frame_unit_size <= 0)
+ break;
+ }
+
+ return 0;
+}
+
typedef struct DemuxerPriv {FILE *f;
size_t temporal_unit_size;
@@ -103,7 +187,8 @@
const Demuxer annexb_demuxer = {.priv_data_size = sizeof(AnnexbInputContext),
.name = "annexb",
- .extension = "obu",
+ .probe = annexb_probe,
+ .probe_sz = PROBE_SIZE,
.open = annexb_open,
.read = annexb_read,
.close = annexb_close,
--- a/tools/input/demuxer.h
+++ b/tools/input/demuxer.h
@@ -34,7 +34,8 @@
typedef struct Demuxer {int priv_data_size;
const char *name;
- const char *extension;
+ int probe_sz;
+ int (*probe)(const uint8_t *data);
int (*open)(DemuxerPriv *ctx, const char *filename,
unsigned fps[2], unsigned *num_frames, unsigned timebase[2]);
int (*read)(DemuxerPriv *ctx, Dav1dData *data);
--- a/tools/input/input.c
+++ b/tools/input/input.c
@@ -33,6 +33,7 @@
#include <string.h>
#include "common/attributes.h"
+#include "common/intops.h"
#include "input/input.h"
#include "input/demuxer.h"
@@ -58,23 +59,6 @@
register_demuxer(section5_demuxer);
}
-static const char *find_extension(const char *const f) {- const size_t l = strlen(f);
-
- if (l == 0) return NULL;
-
- const char *const end = &f[l - 1], *step = end;
- while ((*step >= 'a' && *step <= 'z') ||
- (*step >= 'A' && *step <= 'Z') ||
- (*step >= '0' && *step <= '9'))
- {- step--;
- }
-
- return (step < end && step > f && *step == '.' && step[-1] != '/') ?
- &step[1] : NULL;
-}
-
int input_open(DemuxerContext **const c_out,
const char *const name, const char *const filename,
unsigned fps[2], unsigned *const num_frames, unsigned timebase[2])
@@ -95,22 +79,34 @@
return DAV1D_ERR(ENOPROTOOPT);
}
} else {- const char *const ext = find_extension(filename);
- if (!ext) {- fprintf(stderr, "No extension found for file %s\n", filename);
- return -1;
+ int probe_sz = 0;
+ for (i = 0; i < num_demuxers; i++)
+ probe_sz = imax(probe_sz, demuxers[i]->probe_sz);
+ uint8_t *const probe_data = malloc(probe_sz);
+ if (!probe_data) {+ fprintf(stderr, "Failed to allocate memory\n");
+ return DAV1D_ERR(ENOMEM);
}
+ FILE *f = fopen(filename, "rb");
+ res = !!fread(probe_data, 1, probe_sz, f);
+ fclose(f);
+ if (!res) {+ free(probe_data);
+ fprintf(stderr, "Failed to read probe data\n");
+ return errno ? DAV1D_ERR(errno) : DAV1D_ERR(ENODATA);
+ }
for (i = 0; i < num_demuxers; i++) {- if (!strcmp(demuxers[i]->extension, ext)) {+ if (demuxers[i]->probe(probe_data)) {impl = demuxers[i];
break;
}
}
+ free(probe_data);
if (i == num_demuxers) {fprintf(stderr,
- "Failed to find demuxer for file %s (\"%s\")\n",
- filename, ext);
+ "Failed to probe demuxer for file %s\n",
+ filename);
return DAV1D_ERR(ENOPROTOOPT);
}
}
--- a/tools/input/ivf.c
+++ b/tools/input/ivf.c
@@ -39,6 +39,16 @@
FILE *f;
} IvfInputContext;
+static const uint8_t probe_data[] = {+ 'D', 'K', 'I', 'F',
+ 0, 0, 0x20, 0,
+ 'A', 'V', '0', '1',
+};
+
+static int ivf_probe(const uint8_t *const data) {+ return !memcmp(data, probe_data, sizeof(probe_data));
+}
+
static unsigned rl32(const uint8_t *const p) {return ((uint32_t)p[3] << 24U) | (p[2] << 16U) | (p[1] << 8U) | p[0];
}
@@ -121,7 +131,8 @@
const Demuxer ivf_demuxer = {.priv_data_size = sizeof(IvfInputContext),
.name = "ivf",
- .extension = "ivf",
+ .probe = ivf_probe,
+ .probe_sz = sizeof(probe_data),
.open = ivf_open,
.read = ivf_read,
.close = ivf_close,
--- a/tools/input/parse.h
+++ b/tools/input/parse.h
@@ -48,4 +48,60 @@
return i;
}
+// these functions are based on an implementation from FFmpeg, and relicensed
+// with author's permission
+
+static int leb(const uint8_t *ptr, int sz, size_t *const len) {+ unsigned i = 0, more;
+ *len = 0;
+ do {+ if (!sz--) return -1;
+ const int byte = *ptr++;
+ more = byte & 0x80;
+ const unsigned bits = byte & 0x7f;
+ if (i <= 3 || (i == 4 && bits < (1 << 4)))
+ *len |= bits << (i * 7);
+ else if (bits) return -1;
+ if (++i == 8 && more) return -1;
+ } while (more);
+ return i;
+}
+
+static inline int parse_obu_header(const uint8_t *buf, int buf_size,
+ size_t *const obu_size,
+ enum Dav1dObuType *const type,
+ const int allow_implicit_size)
+{+ int ret, extension_flag, has_size_flag;
+
+ if (!buf_size)
+ return -1;
+ if (*buf & 0x80) // obu_forbidden_bit
+ return -1;
+
+ *type = (*buf & 0x78) >> 3;
+ extension_flag = (*buf & 0x4) >> 2;
+ has_size_flag = (*buf & 0x2) >> 1;
+ // ignore obu_reserved_1bit
+ buf++;
+ buf_size--;
+
+ if (extension_flag) {+ buf++;
+ buf_size--;
+ // ignore fields
+ }
+
+ if (has_size_flag) {+ ret = leb(buf, buf_size, obu_size);
+ if (ret < 0)
+ return -1;
+ return (int) *obu_size + ret + 1 + extension_flag;
+ } else if (!allow_implicit_size)
+ return -1;
+
+ *obu_size = buf_size;
+ return buf_size + 1 + extension_flag;
+}
+
#endif /* DAV1D_INPUT_PARSE_H */
--- a/tools/input/section5.c
+++ b/tools/input/section5.c
@@ -1,6 +1,7 @@
/*
* Copyright © 2019, VideoLAN and dav1d authors
* Copyright © 2019, Two Orioles, LLC
+ * Copyright © 2019, James Almer <jamrial@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -32,9 +33,52 @@
#include <stdlib.h>
#include <string.h>
+#include "dav1d/headers.h"
+
#include "input/demuxer.h"
#include "input/parse.h"
+#define PROBE_SIZE 1024
+
+static int section5_probe(const uint8_t *data) {+ int ret, cnt = 0;
+
+ // Check that the first OBU is a Temporal Delimiter.
+ size_t obu_size;
+ enum Dav1dObuType type;
+ ret = parse_obu_header(data + cnt, PROBE_SIZE - cnt,
+ &obu_size, &type, 0);
+ if (ret < 0 || type != DAV1D_OBU_TD || obu_size > 0)
+ return 0;
+ cnt += ret;
+
+ // look for first frame and accompanying sequence header
+ int seq = 0;
+ while (cnt < PROBE_SIZE) {+ ret = parse_obu_header(data + cnt, PROBE_SIZE - cnt,
+ &obu_size, &type, 0);
+ if (ret < 0)
+ return 0;
+ cnt += ret;
+
+ switch (type) {+ case DAV1D_OBU_SEQ_HDR:
+ seq = 1;
+ break;
+ case DAV1D_OBU_FRAME:
+ case DAV1D_OBU_FRAME_HDR:
+ return seq;
+ case DAV1D_OBU_TD:
+ case DAV1D_OBU_TILE_GRP:
+ return 0;
+ default:
+ break;
+ }
+ }
+
+ return 0;
+}
+
typedef struct DemuxerPriv {FILE *f;
} Section5InputContext;
@@ -132,7 +176,8 @@
const Demuxer section5_demuxer = {.priv_data_size = sizeof(Section5InputContext),
.name = "section5",
- .extension = "obu",
+ .probe = section5_probe,
+ .probe_sz = PROBE_SIZE,
.open = section5_open,
.read = section5_read,
.close = section5_close,