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mpv/demux/demux_lavf.c
wm4 1bae5641ab demux_lavf: fix subtitle seeking before start of the file 
When trying to seek before the start of the file, which usually happens
when using the arrow keys to seek to the start of the file, external
libavformat demuxed subtitles will be invisible. This is because seeking
in the external subtitle file fails, so the subtitle demuxer is left in
a random state.

This is actually similar to the normal seeking path, which has some
fallback code to handle this situation. Add such code to the subtitle
seeking path too.

(Normally, all demuxer support av_seek_frame(), except subtitles, which
support avformat_seek_file() only. The latter was meant to be the "new"
seeking API, but this never really took off, and using it normally seems
to cause worse seeking behavior. Or maybe we just use it incorrectly,
nobody really knows.)
2013-04-21 00:21:23 +02:00

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/*
* Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
// #include <stdio.h>
#include <stdlib.h>
// #include <unistd.h>
#include <limits.h>
#include <stdbool.h>
#include <string.h>
#include <assert.h>
#include <libavformat/avformat.h>
#include <libavformat/avio.h>
#include <libavutil/avutil.h>
#include <libavutil/avstring.h>
#include <libavutil/mathematics.h>
#include <libavutil/opt.h>
#include "compat/libav.h"
#include "config.h"
#include "core/options.h"
#include "core/mp_msg.h"
#include "core/av_opts.h"
#include "core/av_common.h"
#include "core/bstr.h"
#include "stream/stream.h"
#include "demux.h"
#include "stheader.h"
#include "core/m_option.h"
#define INITIAL_PROBE_SIZE STREAM_BUFFER_SIZE
#define PROBE_BUF_SIZE (2 * 1024 * 1024)
#define OPT_BASE_STRUCT struct MPOpts
const m_option_t lavfdopts_conf[] = {
OPT_INTRANGE("probesize", lavfdopts.probesize, 0, 32, INT_MAX),
OPT_STRING("format", lavfdopts.format, 0),
OPT_INTRANGE("analyzeduration", lavfdopts.analyzeduration, 0, 0, INT_MAX),
OPT_INTRANGE("probescore", lavfdopts.probescore, 0, 0, 100),
OPT_STRING("cryptokey", lavfdopts.cryptokey, 0),
OPT_STRING("o", lavfdopts.avopt, 0),
{NULL, NULL, 0, 0, 0, 0, NULL}
};
#define BIO_BUFFER_SIZE 32768
typedef struct lavf_priv {
char *filename;
AVInputFormat *avif;
AVFormatContext *avfc;
AVIOContext *pb;
uint8_t buffer[BIO_BUFFER_SIZE];
int autoselect_sub;
int64_t last_pts;
struct sh_stream **streams; // NULL for unknown streams
int num_streams;
int cur_program;
bool use_dts;
bool seek_by_bytes;
int bitrate;
char *mime_type;
} lavf_priv_t;
static const char *map_demuxer_mime_type[][2] = {
{"audio/aacp", "aac"},
{0}
};
static const char *find_demuxer_from_mime_type(char *mime_type)
{
for (int n = 0; map_demuxer_mime_type[n][0]; n++) {
if (strcasecmp(map_demuxer_mime_type[n][0], mime_type) == 0)
return map_demuxer_mime_type[n][1];
}
return NULL;
}
static int mp_read(void *opaque, uint8_t *buf, int size)
{
struct demuxer *demuxer = opaque;
struct stream *stream = demuxer->stream;
int ret;
ret = stream_read(stream, buf, size);
mp_msg(MSGT_HEADER, MSGL_DBG2,
"%d=mp_read(%p, %p, %d), pos: %"PRId64", eof:%d\n",
ret, stream, buf, size, stream_tell(stream), stream->eof);
return ret;
}
static int64_t mp_seek(void *opaque, int64_t pos, int whence)
{
struct demuxer *demuxer = opaque;
struct stream *stream = demuxer->stream;
int64_t current_pos;
mp_msg(MSGT_HEADER, MSGL_DBG2, "mp_seek(%p, %"PRId64", %d)\n",
stream, pos, whence);
if (whence == SEEK_CUR)
pos += stream_tell(stream);
else if (whence == SEEK_END && stream->end_pos > 0)
pos += stream->end_pos;
else if (whence == SEEK_SET)
pos += stream->start_pos;
else if (whence == AVSEEK_SIZE && stream->end_pos > 0) {
stream_update_size(stream);
return stream->end_pos - stream->start_pos;
} else
return -1;
if (pos < 0)
return -1;
current_pos = stream_tell(stream);
if (stream_seek(stream, pos) == 0) {
stream_reset(stream);
stream_seek(stream, current_pos);
return -1;
}
return pos - stream->start_pos;
}
static int64_t mp_read_seek(void *opaque, int stream_idx, int64_t ts, int flags)
{
struct demuxer *demuxer = opaque;
struct stream *stream = demuxer->stream;
struct lavf_priv *priv = demuxer->priv;
AVStream *st = priv->avfc->streams[stream_idx];
double pts = (double)ts * st->time_base.num / st->time_base.den;
int ret = stream_control(stream, STREAM_CTRL_SEEK_TO_TIME, &pts);
if (ret < 0)
ret = AVERROR(ENOSYS);
return ret;
}
static void list_formats(void)
{
mp_msg(MSGT_DEMUX, MSGL_INFO, "Available lavf input formats:\n");
AVInputFormat *fmt = NULL;
while ((fmt = av_iformat_next(fmt)))
mp_msg(MSGT_DEMUX, MSGL_INFO, "%15s : %s\n", fmt->name, fmt->long_name);
}
static char *remove_prefix(char *s, const char **prefixes)
{
for (int n = 0; prefixes[n]; n++) {
int len = strlen(prefixes[n]);
if (strncmp(s, prefixes[n], len) == 0)
return s + len;
}
return s;
}
static const char *prefixes[] =
{"ffmpeg://", "lavf://", "avdevice://", "av://", NULL};
static int lavf_check_file(demuxer_t *demuxer)
{
struct MPOpts *opts = demuxer->opts;
struct lavfdopts *lavfdopts = &opts->lavfdopts;
AVProbeData avpd;
lavf_priv_t *priv;
int probe_data_size = 0;
int read_size = INITIAL_PROBE_SIZE;
int score;
assert(!demuxer->priv);
demuxer->priv = talloc_zero(NULL, lavf_priv_t);
priv = demuxer->priv;
priv->autoselect_sub = -1;
priv->filename = demuxer->stream->url;
if (!priv->filename) {
priv->filename = "mp:unknown";
mp_msg(MSGT_DEMUX, MSGL_WARN, "Stream url is not set!\n");
}
priv->filename = remove_prefix(priv->filename, prefixes);
char *avdevice_format = NULL;
if (demuxer->stream->type == STREAMTYPE_AVDEVICE) {
// always require filename in the form "format:filename"
char *sep = strchr(priv->filename, ':');
if (!sep) {
mp_msg(MSGT_DEMUX, MSGL_FATAL,
"Must specify filename in 'format:filename' form\n");
return 0;
}
avdevice_format = talloc_strndup(priv, priv->filename,
sep - priv->filename);
priv->filename = sep + 1;
}
char *format = lavfdopts->format;
if (!format)
format = demuxer->stream->lavf_type;
if (!format)
format = avdevice_format;
if (!format && demuxer->stream->mime_type)
format = (char *)find_demuxer_from_mime_type(demuxer->stream->mime_type);
if (format) {
if (strcmp(format, "help") == 0) {
list_formats();
return 0;
}
priv->avif = av_find_input_format(format);
if (!priv->avif) {
mp_msg(MSGT_DEMUX, MSGL_FATAL, "Unknown lavf format %s\n", format);
return 0;
}
mp_msg(MSGT_DEMUX, MSGL_INFO, "Forced lavf %s demuxer\n",
priv->avif->long_name);
goto success;
}
// AVPROBE_SCORE_MAX/4 + 1 is the "recommended" limit. Below that, the user
// is supposed to retry with larger probe sizes until a higher value is
// reached.
int min_probe = AVPROBE_SCORE_MAX/4 + 1;
if (lavfdopts->probescore)
min_probe = lavfdopts->probescore;
avpd.buf = av_mallocz(FFMAX(BIO_BUFFER_SIZE, PROBE_BUF_SIZE) +
FF_INPUT_BUFFER_PADDING_SIZE);
do {
read_size = stream_read(demuxer->stream, avpd.buf + probe_data_size,
read_size);
if (read_size < 0) {
av_free(avpd.buf);
return 0;
}
probe_data_size += read_size;
avpd.filename = priv->filename;
avpd.buf_size = probe_data_size;
score = 0;
priv->avif = av_probe_input_format2(&avpd, probe_data_size > 0, &score);
if (priv->avif) {
mp_msg(MSGT_HEADER, MSGL_V, "Found '%s' at score=%d size=%d.\n",
priv->avif->name, score, probe_data_size);
}
if (priv->avif && score >= min_probe)
break;
priv->avif = NULL;
read_size = FFMIN(2 * read_size, PROBE_BUF_SIZE - probe_data_size);
} while (read_size > 0 && probe_data_size < PROBE_BUF_SIZE);
av_free(avpd.buf);
if (!priv->avif) {
mp_msg(MSGT_HEADER, MSGL_V,
"No format found, try lowering probescore.\n");
return 0;
}
success:
demuxer->filetype = priv->avif->long_name;
if (!demuxer->filetype)
demuxer->filetype = priv->avif->name;
return DEMUXER_TYPE_LAVF;
}
static bool matches_avinputformat_name(struct lavf_priv *priv,
const char *name)
{
const char *avifname = priv->avif->name;
while (1) {
const char *next = strchr(avifname, ',');
if (!next)
return !strcmp(avifname, name);
int len = next - avifname;
if (len == strlen(name) && !memcmp(avifname, name, len))
return true;
avifname = next + 1;
}
}
static uint8_t char2int(char c)
{
if (c >= '0' && c <= '9') return c - '0';
if (c >= 'a' && c <= 'f') return c - 'a' + 10;
if (c >= 'A' && c <= 'F') return c - 'A' + 10;
return 0;
}
static void parse_cryptokey(AVFormatContext *avfc, const char *str)
{
int len = strlen(str) / 2;
uint8_t *key = av_mallocz(len);
int i;
avfc->keylen = len;
avfc->key = key;
for (i = 0; i < len; i++, str += 2)
*key++ = (char2int(str[0]) << 4) | char2int(str[1]);
}
static void handle_stream(demuxer_t *demuxer, int i)
{
lavf_priv_t *priv = demuxer->priv;
AVFormatContext *avfc = priv->avfc;
AVStream *st = avfc->streams[i];
AVCodecContext *codec = st->codec;
struct sh_stream *sh = NULL;
st->discard = AVDISCARD_ALL;
switch (codec->codec_type) {
case AVMEDIA_TYPE_AUDIO: {
sh = new_sh_stream(demuxer, STREAM_AUDIO);
if (!sh)
break;
sh_audio_t *sh_audio = sh->audio;
sh_audio->format = codec->codec_tag;
// probably unneeded
sh_audio->channels = codec->channels;
sh_audio->samplerate = codec->sample_rate;
sh_audio->i_bps = codec->bit_rate / 8;
break;
}
case AVMEDIA_TYPE_VIDEO: {
sh = new_sh_stream(demuxer, STREAM_VIDEO);
if (!sh)
break;
sh_video_t *sh_video = sh->video;
if (st->disposition & AV_DISPOSITION_ATTACHED_PIC)
sh_video->gsh->attached_picture = true;
sh_video->format = codec->codec_tag;
sh_video->disp_w = codec->width;
sh_video->disp_h = codec->height;
/* Try to make up some frame rate value, even if it's not reliable.
* FPS information is needed to support subtitle formats which base
* timing on frame numbers.
* Libavformat seems to report no "reliable" FPS value for AVI files,
* while they are typically constant enough FPS that the value this
* heuristic makes up works with subtitles in practice.
*/
double fps;
if (st->avg_frame_rate.num)
fps = av_q2d(st->avg_frame_rate);
else
fps = 1.0 / FFMAX(av_q2d(st->time_base),
av_q2d(st->codec->time_base) *
st->codec->ticks_per_frame);
sh_video->fps = fps;
sh_video->frametime = 1 / fps;
if (st->sample_aspect_ratio.num)
sh_video->aspect = codec->width * st->sample_aspect_ratio.num
/ (float)(codec->height * st->sample_aspect_ratio.den);
else
sh_video->aspect = codec->width * codec->sample_aspect_ratio.num
/ (float)(codec->height * codec->sample_aspect_ratio.den);
sh_video->i_bps = codec->bit_rate / 8;
mp_msg(MSGT_DEMUX, MSGL_DBG2, "aspect= %d*%d/(%d*%d)\n",
codec->width, codec->sample_aspect_ratio.num,
codec->height, codec->sample_aspect_ratio.den);
break;
}
case AVMEDIA_TYPE_SUBTITLE: {
sh_sub_t *sh_sub;
sh = new_sh_stream(demuxer, STREAM_SUB);
if (!sh)
break;
sh_sub = sh->sub;
if (codec->extradata_size) {
sh_sub->extradata = malloc(codec->extradata_size);
memcpy(sh_sub->extradata, codec->extradata, codec->extradata_size);
sh_sub->extradata_len = codec->extradata_size;
}
st->discard = AVDISCARD_DEFAULT;
break;
}
case AVMEDIA_TYPE_ATTACHMENT: {
AVDictionaryEntry *ftag = av_dict_get(st->metadata, "filename",
NULL, 0);
char *filename = ftag ? ftag->value : NULL;
if (st->codec->codec_id == AV_CODEC_ID_TTF)
demuxer_add_attachment(demuxer, bstr0(filename),
bstr0("application/x-truetype-font"),
(struct bstr){codec->extradata,
codec->extradata_size});
break;
}
default: ;
}
assert(priv->num_streams == i); // directly mapped
MP_TARRAY_APPEND(priv, priv->streams, priv->num_streams, sh);
if (sh) {
sh->codec = mp_codec_from_av_codec_id(codec->codec_id);
sh->lav_headers = avcodec_alloc_context3(codec->codec);
assert(sh->lav_headers);
avcodec_copy_context(sh->lav_headers, codec);
if (st->disposition & AV_DISPOSITION_DEFAULT)
sh->default_track = 1;
if (matches_avinputformat_name(priv, "mpeg"))
sh->demuxer_id = st->id;
AVDictionaryEntry *title = av_dict_get(st->metadata, "title", NULL, 0);
if (title && title->value)
sh->title = talloc_strdup(sh, title->value);
AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL, 0);
if (lang && lang->value)
sh->lang = talloc_strdup(sh, lang->value);
}
}
// Add any new streams that might have been added
static void add_new_streams(demuxer_t *demuxer)
{
lavf_priv_t *priv = demuxer->priv;
while (priv->num_streams < priv->avfc->nb_streams)
handle_stream(demuxer, priv->num_streams);
}
static demuxer_t *demux_open_lavf(demuxer_t *demuxer)
{
struct MPOpts *opts = demuxer->opts;
struct lavfdopts *lavfdopts = &opts->lavfdopts;
AVFormatContext *avfc;
AVDictionaryEntry *t = NULL;
lavf_priv_t *priv = demuxer->priv;
int i;
// do not allow forcing the demuxer
if (!priv->avif)
return NULL;
stream_seek(demuxer->stream, 0);
avfc = avformat_alloc_context();
if (lavfdopts->cryptokey)
parse_cryptokey(avfc, lavfdopts->cryptokey);
if (matches_avinputformat_name(priv, "avi")) {
/* for avi libavformat returns the avi timestamps in .dts,
* some made-up stuff that's not really pts in .pts */
priv->use_dts = true;
demuxer->timestamp_type = TIMESTAMP_TYPE_SORT;
} else {
if (opts->user_correct_pts != 0)
avfc->flags |= AVFMT_FLAG_GENPTS;
}
if (index_mode == 0)
avfc->flags |= AVFMT_FLAG_IGNIDX;
if (lavfdopts->probesize) {
if (av_opt_set_int(avfc, "probesize", lavfdopts->probesize, 0) < 0)
mp_msg(MSGT_HEADER, MSGL_ERR,
"demux_lavf, couldn't set option probesize to %u\n",
lavfdopts->probesize);
}
if (lavfdopts->analyzeduration) {
if (av_opt_set_int(avfc, "analyzeduration",
lavfdopts->analyzeduration * AV_TIME_BASE, 0) < 0)
mp_msg(MSGT_HEADER, MSGL_ERR, "demux_lavf, couldn't set option "
"analyzeduration to %u\n", lavfdopts->analyzeduration);
}
if (lavfdopts->avopt) {
if (parse_avopts(avfc, lavfdopts->avopt) < 0) {
mp_msg(MSGT_HEADER, MSGL_ERR,
"Your options /%s/ look like gibberish to me pal\n",
lavfdopts->avopt);
return NULL;
}
}
if (!(priv->avif->flags & AVFMT_NOFILE) &&
demuxer->stream->type != STREAMTYPE_AVDEVICE)
{
priv->pb = avio_alloc_context(priv->buffer, BIO_BUFFER_SIZE, 0,
demuxer, mp_read, NULL, mp_seek);
priv->pb->read_seek = mp_read_seek;
priv->pb->seekable = demuxer->stream->end_pos
&& (demuxer->stream->flags & MP_STREAM_SEEK) == MP_STREAM_SEEK
? AVIO_SEEKABLE_NORMAL : 0;
avfc->pb = priv->pb;
}
if (avformat_open_input(&avfc, priv->filename, priv->avif, NULL) < 0) {
mp_msg(MSGT_HEADER, MSGL_ERR,
"LAVF_header: avformat_open_input() failed\n");
return NULL;
}
priv->avfc = avfc;
if (avformat_find_stream_info(avfc, NULL) < 0) {
mp_msg(MSGT_HEADER, MSGL_ERR,
"LAVF_header: av_find_stream_info() failed\n");
return NULL;
}
/* Add metadata. */
while ((t = av_dict_get(avfc->metadata, "", t,
AV_DICT_IGNORE_SUFFIX)))
demux_info_add(demuxer, t->key, t->value);
for (i = 0; i < avfc->nb_chapters; i++) {
AVChapter *c = avfc->chapters[i];
uint64_t start = av_rescale_q(c->start, c->time_base,
(AVRational){1, 1000000000});
uint64_t end = av_rescale_q(c->end, c->time_base,
(AVRational){1, 1000000000});
t = av_dict_get(c->metadata, "title", NULL, 0);
demuxer_add_chapter(demuxer, t ? bstr0(t->value) : bstr0(NULL),
start, end);
}
add_new_streams(demuxer);
if (avfc->nb_programs) {
int p;
for (p = 0; p < avfc->nb_programs; p++) {
AVProgram *program = avfc->programs[p];
t = av_dict_get(program->metadata, "title", NULL, 0);
mp_msg(MSGT_HEADER, MSGL_INFO, "LAVF: Program %d %s\n",
program->id, t ? t->value : "");
mp_msg(MSGT_IDENTIFY, MSGL_V, "PROGRAM_ID=%d\n", program->id);
}
}
mp_msg(MSGT_HEADER, MSGL_V, "LAVF: build %d\n", LIBAVFORMAT_BUILD);
demuxer->ts_resets_possible = priv->avif->flags & AVFMT_TS_DISCONT;
// disabled because unreliable per-stream bitrate values returned
// by libavformat trigger this heuristic incorrectly and break things
#if 0
/* libavformat sets bitrate for mpeg based on pts at start and end
* of file, which fails for files with pts resets. So calculate our
* own bitrate estimate. */
if (priv->avif->flags & AVFMT_TS_DISCONT) {
for (int i = 0; i < avfc->nb_streams; i++)
priv->bitrate += avfc->streams[i]->codec->bit_rate;
/* pts-based is more accurate if there are no resets; try to make
* a somewhat reasonable guess */
if (!avfc->duration || avfc->duration == AV_NOPTS_VALUE
|| priv->bitrate && (avfc->bit_rate < priv->bitrate / 2
|| avfc->bit_rate > priv->bitrate * 2))
priv->seek_by_bytes = true;
if (!priv->bitrate)
priv->bitrate = 1440000;
}
#endif
demuxer->accurate_seek = !priv->seek_by_bytes;
return demuxer;
}
static int destroy_avpacket(void *pkt)
{
av_free_packet(pkt);
return 0;
}
static int demux_lavf_fill_buffer(demuxer_t *demux, demux_stream_t *dsds)
{
lavf_priv_t *priv = demux->priv;
demux_packet_t *dp;
mp_msg(MSGT_DEMUX, MSGL_DBG2, "demux_lavf_fill_buffer()\n");
demux->filepos = stream_tell(demux->stream);
AVPacket *pkt = talloc(NULL, AVPacket);
if (av_read_frame(priv->avfc, pkt) < 0) {
talloc_free(pkt);
return 0;
}
talloc_set_destructor(pkt, destroy_avpacket);
add_new_streams(demux);
assert(pkt->stream_index >= 0 && pkt->stream_index < priv->num_streams);
AVStream *st = priv->avfc->streams[pkt->stream_index];
struct sh_stream *stream = priv->streams[pkt->stream_index];
if (stream && stream->type == STREAM_SUB && demux->sub->id < 0 &&
stream->demuxer_id == priv->autoselect_sub)
{
priv->autoselect_sub = -1;
demux->sub->id = stream->stream_index;
}
if (!demuxer_stream_is_selected(demux, stream)) {
talloc_free(pkt);
return 1;
}
// If the packet has pointers to temporary fields that could be
// overwritten/freed by next av_read_frame(), copy them to persistent
// allocations so we can safely queue the packet for any length of time.
if (av_dup_packet(pkt) < 0)
abort();
dp = new_demux_packet_fromdata(pkt->data, pkt->size);
dp->avpacket = pkt;
int64_t ts = priv->use_dts ? pkt->dts : pkt->pts;
if (ts == AV_NOPTS_VALUE && (st->disposition & AV_DISPOSITION_ATTACHED_PIC))
ts = 0;
if (ts != AV_NOPTS_VALUE) {
dp->pts = ts * av_q2d(st->time_base);
priv->last_pts = dp->pts * AV_TIME_BASE;
// always set duration for subtitles, even if AV_PKT_FLAG_KEY isn't set,
// otherwise they will stay on screen to long if e.g. ASS is demuxed
// from mkv
if ((stream->type == STREAM_SUB || (pkt->flags & AV_PKT_FLAG_KEY)) &&
pkt->convergence_duration > 0)
dp->duration = pkt->convergence_duration * av_q2d(st->time_base);
}
dp->pos = demux->filepos;
dp->keyframe = pkt->flags & AV_PKT_FLAG_KEY;
demuxer_add_packet(demux, stream, dp);
return 1;
}
static void demux_seek_lavf(demuxer_t *demuxer, float rel_seek_secs,
float audio_delay, int flags)
{
lavf_priv_t *priv = demuxer->priv;
int avsflags = 0;
mp_msg(MSGT_DEMUX, MSGL_DBG2, "demux_seek_lavf(%p, %f, %f, %d)\n",
demuxer, rel_seek_secs, audio_delay, flags);
if (priv->seek_by_bytes) {
int64_t pos = demuxer->filepos;
rel_seek_secs *= priv->bitrate / 8;
pos += rel_seek_secs;
av_seek_frame(priv->avfc, -1, pos, AVSEEK_FLAG_BYTE);
return;
}
if (flags & SEEK_ABSOLUTE)
priv->last_pts = 0;
else if (rel_seek_secs < 0)
avsflags = AVSEEK_FLAG_BACKWARD;
if (flags & SEEK_FORWARD)
avsflags = 0;
else if (flags & SEEK_BACKWARD)
avsflags = AVSEEK_FLAG_BACKWARD;
if (flags & SEEK_FACTOR) {
if (demuxer->movi_end > 0 && demuxer->ts_resets_possible &&
!(priv->avif->flags & AVFMT_NO_BYTE_SEEK))
{
avsflags |= AVSEEK_FLAG_BYTE;
priv->last_pts = (demuxer->movi_end - demuxer->movi_start) *
rel_seek_secs;
} else if (priv->avfc->duration != 0 &&
priv->avfc->duration != AV_NOPTS_VALUE)
{
priv->last_pts = rel_seek_secs * priv->avfc->duration;
}
} else {
priv->last_pts += rel_seek_secs * AV_TIME_BASE;
}
if (!priv->avfc->iformat->read_seek2) {
// Normal seeking.
int r = av_seek_frame(priv->avfc, -1, priv->last_pts, avsflags);
if (r < 0 && (avsflags & AVSEEK_FLAG_BACKWARD)) {
// When seeking before the beginning of the file, and seeking fails,
// try again without the backwards flag to make it seek to the
// beginning.
avsflags &= ~AVSEEK_FLAG_BACKWARD;
av_seek_frame(priv->avfc, -1, priv->last_pts, avsflags);
}
} else {
// av_seek_frame() won't work. Use "new" seeking API. We don't use this
// API by default, because there are some major issues.
// Set max_ts==ts, so that demuxing starts from an earlier position in
// the worst case.
int r = avformat_seek_file(priv->avfc, -1, INT64_MIN,
priv->last_pts, priv->last_pts, avsflags);
// Similar issue as in the normal seeking codepath.
if (r < 0) {
avformat_seek_file(priv->avfc, -1, INT64_MIN,
priv->last_pts, INT64_MAX, avsflags);
}
}
}
static int demux_lavf_control(demuxer_t *demuxer, int cmd, void *arg)
{
lavf_priv_t *priv = demuxer->priv;
switch (cmd) {
case DEMUXER_CTRL_CORRECT_PTS:
return DEMUXER_CTRL_OK;
case DEMUXER_CTRL_GET_TIME_LENGTH:
if (priv->seek_by_bytes) {
/* Our bitrate estimate may be better than would be used in
* otherwise similar fallback code at higher level */
if (demuxer->movi_end <= 0)
return DEMUXER_CTRL_DONTKNOW;
*(double *)arg = (demuxer->movi_end - demuxer->movi_start) * 8 /
priv->bitrate;
return DEMUXER_CTRL_GUESS;
}
if (priv->avfc->duration == 0 || priv->avfc->duration == AV_NOPTS_VALUE)
return DEMUXER_CTRL_DONTKNOW;
*((double *)arg) = (double)priv->avfc->duration / AV_TIME_BASE;
return DEMUXER_CTRL_OK;
case DEMUXER_CTRL_GET_START_TIME:
*((double *)arg) = priv->avfc->start_time == AV_NOPTS_VALUE ?
0 : (double)priv->avfc->start_time / AV_TIME_BASE;
return DEMUXER_CTRL_OK;
case DEMUXER_CTRL_SWITCHED_TRACKS:
{
for (int n = 0; n < priv->num_streams; n++) {
struct sh_stream *stream = priv->streams[n];
AVStream *st = priv->avfc->streams[n];
if (stream && stream->type != STREAM_SUB) {
bool selected = demuxer_stream_is_selected(demuxer, stream);
st->discard = selected ? AVDISCARD_NONE : AVDISCARD_ALL;
}
}
return DEMUXER_CTRL_OK;
}
case DEMUXER_CTRL_AUTOSELECT_SUBTITLE:
{
demuxer->sub->id = -1;
priv->autoselect_sub = *((int *)arg);
return DEMUXER_CTRL_OK;
}
case DEMUXER_CTRL_IDENTIFY_PROGRAM:
{
demux_program_t *prog = arg;
AVProgram *program;
int p, i;
int start;
add_new_streams(demuxer);
prog->vid = prog->aid = prog->sid = -2;
if (priv->avfc->nb_programs < 1)
return DEMUXER_CTRL_DONTKNOW;
if (prog->progid == -1) {
p = 0;
while (p < priv->avfc->nb_programs && priv->avfc->programs[p]->id != priv->cur_program)
p++;
p = (p + 1) % priv->avfc->nb_programs;
} else {
for (i = 0; i < priv->avfc->nb_programs; i++)
if (priv->avfc->programs[i]->id == prog->progid)
break;
if (i == priv->avfc->nb_programs)
return DEMUXER_CTRL_DONTKNOW;
p = i;
}
start = p;
redo:
prog->vid = prog->aid = prog->sid = -2;
program = priv->avfc->programs[p];
for (i = 0; i < program->nb_stream_indexes; i++) {
struct sh_stream *stream = priv->streams[program->stream_index[i]];
if (stream) {
switch (stream->type) {
case STREAM_VIDEO:
if (prog->vid == -2)
prog->vid = stream->demuxer_id;
break;
case STREAM_AUDIO:
if (prog->aid == -2)
prog->aid = stream->demuxer_id;
break;
case STREAM_SUB:
if (prog->sid == -2)
prog->sid = stream->demuxer_id;
break;
}
}
}
if (prog->progid == -1 && prog->vid == -2 && prog->aid == -2) {
p = (p + 1) % priv->avfc->nb_programs;
if (p == start)
return DEMUXER_CTRL_DONTKNOW;
goto redo;
}
priv->cur_program = prog->progid = program->id;
return DEMUXER_CTRL_OK;
}
case DEMUXER_CTRL_RESYNC:
/* NOTE:
*
* We actually want to call ff_read_frame_flush() here, but it is
* internal.
*
* This function call seems to do the same for now.
*
* Once ff_read_frame_flush() is exported in some way, change this to
* call the new API instead of relying on av_seek_frame() to do this
* for us.
*/
avio_flush(priv->avfc->pb);
av_seek_frame(priv->avfc, 0, avio_tell(priv->avfc->pb),
AVSEEK_FLAG_BYTE);
avio_flush(priv->avfc->pb);
return DEMUXER_CTRL_OK;
default:
return DEMUXER_CTRL_NOTIMPL;
}
}
static void demux_close_lavf(demuxer_t *demuxer)
{
lavf_priv_t *priv = demuxer->priv;
if (priv) {
if (priv->avfc) {
av_freep(&priv->avfc->key);
avformat_close_input(&priv->avfc);
}
av_freep(&priv->pb);
talloc_free(priv);
demuxer->priv = NULL;
}
}
const demuxer_desc_t demuxer_desc_lavf = {
"libavformat demuxer",
"lavf",
"libavformat",
"Michael Niedermayer",
"supports many formats, requires libavformat",
DEMUXER_TYPE_LAVF,
1,
lavf_check_file,
demux_lavf_fill_buffer,
demux_open_lavf,
demux_close_lavf,
demux_seek_lavf,
demux_lavf_control
};
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