ref: c48ea15febf8f6a3a34e998f04c36861f0fc4aed
dir: /tools/input/annexb.c/
/*
* Copyright © 2018, VideoLAN and dav1d authors
* Copyright © 2018, Two Orioles, LLC
* Copyright © 2019, James Almer <[email protected]>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <stdio.h>
#include <stdint.h>
#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 += (int)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 += (int)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;
size_t frame_unit_size;
} AnnexbInputContext;
static int annexb_open(AnnexbInputContext *const c, const char *const file,
unsigned fps[2], unsigned *const num_frames, unsigned timebase[2])
{
int res;
size_t len;
if (!(c->f = fopen(file, "rb"))) {
fprintf(stderr, "Failed to open %s: %s\n", file, strerror(errno));
return -1;
}
// TODO: Parse sequence header and read timing info if any.
fps[0] = 25;
fps[1] = 1;
timebase[0] = 25;
timebase[1] = 1;
for (*num_frames = 0;; (*num_frames)++) {
res = leb128(c->f, &len);
if (res < 0)
break;
fseeko(c->f, len, SEEK_CUR);
}
fseeko(c->f, 0, SEEK_SET);
return 0;
}
static int annexb_read(AnnexbInputContext *const c, Dav1dData *const data) {
size_t len;
int res;
if (!c->temporal_unit_size) {
res = leb128(c->f, &c->temporal_unit_size);
if (res < 0) return -1;
}
if (!c->frame_unit_size) {
res = leb128(c->f, &c->frame_unit_size);
if (res < 0 || (c->frame_unit_size + res) > c->temporal_unit_size) return -1;
c->temporal_unit_size -= res;
}
res = leb128(c->f, &len);
if (res < 0 || (len + res) > c->frame_unit_size) return -1;
uint8_t *ptr = dav1d_data_create(data, len);
if (!ptr) return -1;
c->temporal_unit_size -= len + res;
c->frame_unit_size -= len + res;
if (fread(ptr, len, 1, c->f) != 1) {
fprintf(stderr, "Failed to read frame data: %s\n", strerror(errno));
dav1d_data_unref(data);
return -1;
}
return 0;
}
static void annexb_close(AnnexbInputContext *const c) {
fclose(c->f);
}
const Demuxer annexb_demuxer = {
.priv_data_size = sizeof(AnnexbInputContext),
.name = "annexb",
.probe = annexb_probe,
.probe_sz = PROBE_SIZE,
.open = annexb_open,
.read = annexb_read,
.close = annexb_close,
};