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mpv/demux/demux_lavf.c
wm4 a49ab7cc2f demux: make determining seek capability generic 
Instead of having each demuxer do it (only demux_mkv actually did...),
let generic code determine whether the file is seekable. This requires
adding exceptions to demuxers where the stream is not seekable, but the
demuxer is.

Sort-of try to improve handling of unseekable files in the player. Exit
early if the file is determined to be unseekable, instead of resetting
all decoders and then performing a pointless seek.

Add an exception to allow seeking if the file is not seekable, but the
stream cache is enabled. Print a warning in this case, because seeking
outside the cache (which we can't prevent since the demuxer is not aware
of this problem) still messes everything up.
2013-11-03 19:21:47 +01:00

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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 "mpvcore/options.h"
#include "mpvcore/mp_msg.h"
#include "mpvcore/av_opts.h"
#include "mpvcore/av_common.h"
#include "mpvcore/bstr.h"
#include "stream/stream.h"
#include "demux.h"
#include "stheader.h"
#include "mpvcore/m_option.h"
#define INITIAL_PROBE_SIZE STREAM_BUFFER_SIZE
#define PROBE_BUF_SIZE FFMIN(STREAM_MAX_BUFFER_SIZE, 2 * 1024 * 1024)
#define OPT_BASE_STRUCT struct MPOpts
// Should correspond to IO_BUFFER_SIZE in libavformat/aviobuf.c (not public)
// libavformat (almost) always reads data in blocks of this size.
#define BIO_BUFFER_SIZE 32768
const m_option_t lavfdopts_conf[] = {
OPT_INTRANGE("probesize", lavfdopts.probesize, 0, 32, INT_MAX),
OPT_STRING("format", lavfdopts.format, 0),
OPT_FLOATRANGE("analyzeduration", lavfdopts.analyzeduration, 0, 0, 3600),
OPT_INTRANGE("buffersize", lavfdopts.buffersize, 0, 1, 10 * 1024 * 1024,
OPTDEF_INT(BIO_BUFFER_SIZE)),
OPT_FLAG("allow-mimetype", lavfdopts.allow_mimetype, 0),
OPT_INTRANGE("probescore", lavfdopts.probescore, 0, 0, 100),
OPT_STRING("cryptokey", lavfdopts.cryptokey, 0),
OPT_CHOICE("genpts-mode", lavfdopts.genptsmode, 0,
({"auto", 0}, {"lavf", 1}, {"builtin", 2}, {"no", 3})),
OPT_STRING("o", lavfdopts.avopt, 0),
{NULL, NULL, 0, 0, 0, 0, NULL}
};
#define MAX_PKT_QUEUE 50
typedef struct lavf_priv {
char *filename;
const struct format_hack *format_hack;
AVInputFormat *avif;
AVFormatContext *avfc;
AVIOContext *pb;
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;
bool genpts_hack;
AVPacket *packets[MAX_PKT_QUEUE];
int num_packets;
} lavf_priv_t;
struct format_hack {
const char *ff_name;
const char *mime_type;
int probescore;
float analyzeduration;
};
static const struct format_hack format_hacks[] = {
{"aac", "audio/aacp", 25, 0.5},
{"aac", "audio/aac", 25, 0.5},
{"mp3", "audio/mpeg", 25, 0.5},
{0}
};
static const char *format_blacklist[] = {
"tty", // Useless non-sense, sometimes breaks MLP2 subreader.c fallback
0
};
static const struct format_hack *find_format_from_mime_type(char *mime_type)
{
for (int n = 0; format_hacks[n].ff_name; n++) {
if (strcasecmp(format_hacks[n].mime_type, mime_type) == 0)
return &format_hacks[n];
}
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_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, enum demux_check check)
{
struct MPOpts *opts = demuxer->opts;
struct lavfdopts *lavfdopts = &opts->lavfdopts;
struct stream *s = demuxer->stream;
lavf_priv_t *priv;
assert(!demuxer->priv);
demuxer->priv = talloc_zero(NULL, lavf_priv_t);
priv = demuxer->priv;
priv->filename = s->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 (s->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 -1;
}
avdevice_format = talloc_strndup(priv, priv->filename,
sep - priv->filename);
priv->filename = sep + 1;
}
const char *expected_format = NULL;
int expected_format_probescore = AVPROBE_SCORE_MAX;
char *mime_type = demuxer->stream->mime_type;
if (lavfdopts->allow_mimetype && mime_type) {
priv->format_hack = find_format_from_mime_type(mime_type);
if (priv->format_hack) {
expected_format = priv->format_hack->ff_name;
expected_format_probescore = priv->format_hack->probescore;
}
}
const char *format = lavfdopts->format;
if (!format)
format = s->lavf_type;
if (!format)
format = avdevice_format;
if (format) {
if (strcmp(format, "help") == 0) {
list_formats();
return -1;
}
priv->avif = av_find_input_format(format);
if (!priv->avif) {
mp_msg(MSGT_DEMUX, MSGL_FATAL, "Unknown lavf format %s\n", format);
return -1;
}
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;
AVProbeData avpd = {
// Disable file-extension matching with normal checks
.filename = check <= DEMUX_CHECK_REQUEST ? priv->filename : NULL,
.buf_size = 0,
.buf = av_mallocz(PROBE_BUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE),
};
while (avpd.buf_size < PROBE_BUF_SIZE) {
int nsize = av_clip(avpd.buf_size * 2, INITIAL_PROBE_SIZE,
PROBE_BUF_SIZE);
bstr buf = stream_peek(s, nsize);
if (buf.len <= avpd.buf_size)
break;
memcpy(avpd.buf, buf.start, buf.len);
avpd.buf_size = buf.len;
int score = 0;
priv->avif = av_probe_input_format2(&avpd, avpd.buf_size > 0, &score);
if (priv->avif) {
mp_msg(MSGT_HEADER, MSGL_V, "Found '%s' at score=%d size=%d.\n",
priv->avif->name, score, avpd.buf_size);
if (score >= min_probe)
break;
if (expected_format) {
if (strcmp(priv->avif->name, expected_format) == 0 &&
score >= expected_format_probescore)
break;
}
}
priv->avif = NULL;
}
av_free(avpd.buf);
if (priv->avif && !format) {
for (int n = 0; format_blacklist[n]; n++) {
if (strcmp(format_blacklist[n], priv->avif->name) == 0) {
mp_msg(MSGT_HEADER, MSGL_V, "Format blacklisted.\n");
priv->avif = NULL;
break;
}
}
}
if (!priv->avif) {
mp_msg(MSGT_HEADER, MSGL_V,
"No format found, try lowering probescore or forcing the format.\n");
return -1;
}
success:
demuxer->filetype = priv->avif->long_name;
if (!demuxer->filetype)
demuxer->filetype = priv->avif->name;
return 0;
}
static bool matches_avinputformat_name(struct lavf_priv *priv,
const char *name)
{
// At least mp4 has name="mov,mp4,m4a,3gp,3g2,mj2", so we split the name
// on "," in general.
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 select_tracks(struct demuxer *demuxer, int start)
{
lavf_priv_t *priv = demuxer->priv;
for (int n = start; n < priv->num_streams; n++) {
struct sh_stream *stream = priv->streams[n];
AVStream *st = priv->avfc->streams[n];
bool selected = stream && demuxer_stream_is_selected(demuxer, stream) &&
!stream->attached_picture;
st->discard = selected ? AVDISCARD_DEFAULT : AVDISCARD_ALL;
}
}
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;
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
mp_chmap_from_channels(&sh_audio->channels, codec->channels);
if (codec->channel_layout)
mp_chmap_from_lavc(&sh_audio->channels, codec->channel_layout);
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->attached_picture = new_demux_packet_from(st->attached_pic.data,
st->attached_pic.size);
sh->attached_picture->pts = 0;
talloc_steal(sh, sh->attached_picture);
sh->attached_picture->keyframe = 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;
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;
}
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 = codec;
if (st->disposition & AV_DISPOSITION_DEFAULT)
sh->default_track = 1;
if (matches_avinputformat_name(priv, "mpeg") ||
matches_avinputformat_name(priv, "mpegts"))
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);
}
select_tracks(demuxer, i);
}
// 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 void add_metadata(demuxer_t *demuxer, AVDictionary *metadata)
{
AVDictionaryEntry *t = NULL;
while ((t = av_dict_get(metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
demux_info_add(demuxer, t->key, t->value);
}
static int demux_open_lavf(demuxer_t *demuxer, enum demux_check check)
{
struct MPOpts *opts = demuxer->opts;
struct lavfdopts *lavfdopts = &opts->lavfdopts;
AVFormatContext *avfc;
AVDictionaryEntry *t = NULL;
float analyze_duration = 0;
int i;
if (lavf_check_file(demuxer, check) < 0)
return -1;
lavf_priv_t *priv = demuxer->priv;
if (!priv)
return -1;
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 {
int mode = lavfdopts->genptsmode;
if (mode == 0 && opts->correct_pts)
mode = demuxer->stream->uncached_type == STREAMTYPE_DVD ? 2 : 1;
if (mode == 1)
avfc->flags |= AVFMT_FLAG_GENPTS;
if (mode == 2)
priv->genpts_hack = true;
}
if (opts->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 (priv->format_hack && priv->format_hack->analyzeduration)
analyze_duration = priv->format_hack->analyzeduration;
if (lavfdopts->analyzeduration)
analyze_duration = lavfdopts->analyzeduration;
if (analyze_duration > 0) {
if (av_opt_set_int(avfc, "analyzeduration",
analyze_duration * AV_TIME_BASE, 0) < 0)
mp_msg(MSGT_HEADER, MSGL_ERR, "demux_lavf, couldn't set option "
"analyzeduration to %f\n", analyze_duration);
}
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 -1;
}
}
if ((priv->avif->flags & AVFMT_NOFILE) ||
demuxer->stream->type == STREAMTYPE_AVDEVICE)
{
// This might be incorrect.
demuxer->seekable = true;
} else {
void *buffer = av_malloc(lavfdopts->buffersize);
if (!buffer)
return -1;
priv->pb = avio_alloc_context(buffer, lavfdopts->buffersize, 0,
demuxer, mp_read, NULL, mp_seek);
if (!priv->pb) {
av_free(buffer);
return -1;
}
priv->pb->read_seek = mp_read_seek;
priv->pb->seekable = demuxer->seekable ? AVIO_SEEKABLE_NORMAL : 0;
avfc->pb = priv->pb;
}
AVDictionary *dopts = NULL;
if (matches_avinputformat_name(priv, "rtsp")) {
const char *transport = NULL;
switch (opts->network_rtsp_transport) {
case 1: transport = "udp"; break;
case 2: transport = "tcp"; break;
case 3: transport = "http"; break;
}
if (transport)
av_dict_set(&dopts, "rtsp_transport", transport, 0);
}
if (avformat_open_input(&avfc, priv->filename, priv->avif, &dopts) < 0) {
mp_msg(MSGT_HEADER, MSGL_ERR,
"LAVF_header: avformat_open_input() failed\n");
av_dict_free(&dopts);
return -1;
}
t = NULL;
while ((t = av_dict_get(dopts, "", t, AV_DICT_IGNORE_SUFFIX))) {
mp_msg(MSGT_OPEN, MSGL_V, "[lavf] Could not set demux option %s=%s\n",
t->key, t->value);
}
av_dict_free(&dopts);
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 -1;
}
mp_msg(MSGT_HEADER, MSGL_V, "demux_lavf: avformat_find_stream_info() "
"finished after %"PRId64" bytes.\n", stream_tell(demuxer->stream));
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, i);
t = NULL;
while ((t = av_dict_get(c->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
demuxer_add_chapter_info(demuxer, i, bstr0(t->key),
bstr0(t->value));
}
}
add_new_streams(demuxer);
add_metadata(demuxer, avfc->metadata);
// Often useful with OGG audio-only files, which have metadata in the audio
// track metadata instead of the main metadata.
if (demuxer->num_streams == 1) {
for (int n = 0; n < priv->num_streams; n++) {
if (priv->streams[n])
add_metadata(demuxer, avfc->streams[n]->metadata);
}
}
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 0;
}
static void seek_reset(demuxer_t *demux)
{
lavf_priv_t *priv = demux->priv;
for (int n = 0; n < priv->num_packets; n++)
talloc_free(priv->packets[n]);
priv->num_packets = 0;
}
static void destroy_avpacket(void *pkt)
{
av_free_packet(pkt);
}
static int read_more_av_packets(demuxer_t *demux)
{
lavf_priv_t *priv = demux->priv;
if (priv->num_packets >= MAX_PKT_QUEUE)
return -1;
demux->filepos = stream_tell(demux->stream);
AVPacket *pkt = talloc(NULL, AVPacket);
if (av_read_frame(priv->avfc, pkt) < 0) {
talloc_free(pkt);
return -2; // eof
}
talloc_set_destructor(pkt, destroy_avpacket);
add_new_streams(demux);
assert(pkt->stream_index >= 0 && pkt->stream_index < priv->num_streams);
struct sh_stream *stream = priv->streams[pkt->stream_index];
if (!demuxer_stream_is_selected(demux, stream)) {
talloc_free(pkt);
return 0; // skip
}
// 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();
priv->packets[priv->num_packets++] = pkt;
talloc_steal(priv, pkt);
return 1;
}
static int read_av_packet(demuxer_t *demux, AVPacket **pkt)
{
lavf_priv_t *priv = demux->priv;
if (priv->num_packets < 1) {
int r = read_more_av_packets(demux);
if (r <= 0)
return r;
}
AVPacket *next = priv->packets[0];
if (priv->genpts_hack && next->dts != AV_NOPTS_VALUE) {
int n = 1;
while (next->pts == AV_NOPTS_VALUE) {
while (n >= priv->num_packets) {
if (read_more_av_packets(demux) < 0)
goto end; // queue limit or EOF reached - just use as is
}
AVPacket *cur = priv->packets[n];
if (cur->stream_index == next->stream_index) {
if (next->dts < cur->dts && cur->pts != cur->dts)
next->pts = cur->dts;
}
n++;
}
}
end:
MP_TARRAY_REMOVE_AT(priv->packets, priv->num_packets, 0);
*pkt = next;
return 1;
}
static int demux_lavf_fill_buffer(demuxer_t *demux)
{
lavf_priv_t *priv = demux->priv;
demux_packet_t *dp;
mp_msg(MSGT_DEMUX, MSGL_DBG2, "demux_lavf_fill_buffer()\n");
AVPacket *pkt;
int r = read_av_packet(demux, &pkt);
if (r <= 0)
return r == 0; // don't signal EOF if skipping a packet
AVStream *st = priv->avfc->streams[pkt->stream_index];
struct sh_stream *stream = priv->streams[pkt->stream_index];
dp = new_demux_packet_fromdata(pkt->data, pkt->size);
dp->avpacket = talloc_steal(dp, pkt);
int64_t ts = priv->use_dts ? pkt->dts : pkt->pts;
if (ts != AV_NOPTS_VALUE) {
dp->pts = ts * av_q2d(st->time_base);
priv->last_pts = dp->pts * AV_TIME_BASE;
dp->duration = pkt->duration * av_q2d(st->time_base);
if (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;
// Use only one stream for stream_pts, otherwise PTS might be jumpy.
if (stream->type == STREAM_VIDEO) {
double pts;
if (stream_control(demux->stream, STREAM_CTRL_GET_CURRENT_TIME, &pts) > 0)
dp->stream_pts = pts;
}
demuxer_add_packet(demux, stream, dp);
return 1;
}
static void demux_seek_lavf(demuxer_t *demuxer, float rel_seek_secs, int flags)
{
lavf_priv_t *priv = demuxer->priv;
int avsflags = 0;
mp_msg(MSGT_DEMUX, MSGL_DBG2, "demux_seek_lavf(%p, %f, %d)\n",
demuxer, rel_seek_secs, flags);
seek_reset(demuxer);
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) {
struct stream *s = demuxer->stream;
if (s->end_pos > 0 && demuxer->ts_resets_possible &&
!(priv->avif->flags & AVFMT_NO_BYTE_SEEK))
{
avsflags |= AVSEEK_FLAG_BYTE;
priv->last_pts = (s->end_pos - s->start_pos) * 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.
// To make this horrible situation even worse, some lavf demuxers have
// broken timebase handling (everything that uses
// ff_subtitles_queue_seek()), and always uses the stream timebase. So
// we use the timebase and stream index of the first enabled stream
// (i.e. a stream which can participate in seeking).
int stream_index = -1;
AVRational time_base = {1, AV_TIME_BASE};
for (int n = 0; n < priv->num_streams; n++) {
struct sh_stream *stream = priv->streams[n];
AVStream *st = priv->avfc->streams[n];
if (stream && st->discard != AVDISCARD_ALL) {
stream_index = n;
time_base = st->time_base;
break;
}
}
int64_t pts = priv->last_pts;
if (pts != AV_NOPTS_VALUE)
pts = pts / (double)AV_TIME_BASE * av_q2d(av_inv_q(time_base));
int r = avformat_seek_file(priv->avfc, stream_index, INT64_MIN,
pts, pts, avsflags);
// Similar issue as in the normal seeking codepath.
if (r < 0) {
avformat_seek_file(priv->avfc, stream_index, INT64_MIN,
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_GET_TIME_LENGTH:
if (priv->seek_by_bytes) {
struct stream *s = demuxer->stream;
/* Our bitrate estimate may be better than would be used in
* otherwise similar fallback code at higher level */
if (s->end_pos <= 0)
return DEMUXER_CTRL_DONTKNOW;
*(double *)arg = (s->end_pos - s->start_pos) * 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:
{
select_tracks(demuxer, 0);
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, stream_tell(demuxer->stream),
AVSEEK_FLAG_BYTE);
seek_reset(demuxer);
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);
}
if (priv->pb)
av_freep(&priv->pb->buffer);
av_freep(&priv->pb);
talloc_free(priv);
demuxer->priv = NULL;
}
}
const demuxer_desc_t demuxer_desc_lavf = {
.name = "lavf",
.desc = "libavformat",
.fill_buffer = demux_lavf_fill_buffer,
.open = demux_open_lavf,
.close = demux_close_lavf,
.seek = demux_seek_lavf,
.control = demux_lavf_control,
};
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