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mpv/demux/demux_lavf.c
wm4 f9f2e1cc4e demux: hack for instant stream switching 
This removes the delay when switching audio tracks in mkv or mp4 files.
Other formats are not enabled, because it's not clear whether the
demuxers fulfill the requirements listed in demux.h. (Many formats
definitely do not with libavformat.)

Background:

The demuxer packet cache buffers a certain amount of packets. This
includes only packets from selected streams. We discard packets from
other streams for various reasons. This introduces a problem: switching
to a different audio track introduces a delay. The delay is as big as
the demuxer packet cache buffer, because while the file was read ahead
to fill the packet buffer, the process of reading packets also discarded
all packets from the previously not selected audio stream. Once the
remaining packet buffer has been played, new audio packets are available
and you hear audio again.

We could probably just not discard packets from unselected streams. But
this would require additional memory and CPU resources, and also it's
hard to tell when packets from unused streams should be discarded (we
don't want to keep them forever; it'd be a memory leak).

We could also issue a player hr-seek to the current playback position,
which would solve the problem in 1 line of code or so. But this can be
rather slow.

So what we do in this commit instead is: we just seek back to the
position where our current packet buffer starts, and start demuxing from
this position again. This way we can get the "past" packets for the
newly selected stream. For streams which were already selected the
packets are simply discarded until the previous position is reached
again.

That latter part is the hard part. We really want to skip packets
exactly until the position where we left off previously, or we will skip
packets or feed packets to the decoder twice. If we assume that the
demuxer is deterministic (returns exactly the same packets after a seek
to a previous position), then we can try to check whether it's the same
packet as the one at the end of the packet buffer. If it is, we know
that the packet after it is where we left off last time.

Unfortunately, this is not very robust, and maybe it can't be made
robust. Currently we use the demux_packet.pos field as unique packet
ID - which works fine in some scenarios, but will break in arbitrary
ways if the basic requirement to the demuxer (as listed in the demux.h
additions) are broken. Thus, this is enabled only for the internal mkv
demuxer and the libavformat mp4 demuxer.

(libavformat mkv does not work, because the packet positions are not
unique. Probably could be fixed upstream, but it's not clear whether
it's a bug or a feature.)
2015-02-13 21:17:17 +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 <stdlib.h>
#include <limits.h>
#include <stdbool.h>
#include <string.h>
#include <strings.h>
#include <assert.h>
#include "config.h"
#include <libavformat/avformat.h>
#include <libavformat/avio.h>
#include <libavutil/avutil.h>
#include <libavutil/avstring.h>
#include <libavutil/mathematics.h>
#if HAVE_AVCODEC_REPLAYGAIN_SIDE_DATA
# include <libavutil/replaygain.h>
#endif
#if HAVE_AV_DISPLAYMATRIX
# include <libavutil/display.h>
#endif
#include <libavutil/opt.h>
#include "options/options.h"
#include "common/msg.h"
#include "common/tags.h"
#include "common/av_common.h"
#include "misc/bstr.h"
#include "stream/stream.h"
#include "demux.h"
#include "stheader.h"
#include "options/m_option.h"
#define INITIAL_PROBE_SIZE STREAM_BUFFER_SIZE
#define PROBE_BUF_SIZE FFMIN(STREAM_MAX_BUFFER_SIZE, 2 * 1024 * 1024)
// 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
#define OPT_BASE_STRUCT struct demux_lavf_opts
struct demux_lavf_opts {
int probesize;
int probescore;
float analyzeduration;
int buffersize;
int allow_mimetype;
char *format;
char *cryptokey;
char **avopts;
int genptsmode;
};
const struct m_sub_options demux_lavf_conf = {
.opts = (const m_option_t[]) {
OPT_INTRANGE("probesize", probesize, 0, 32, INT_MAX),
OPT_STRING("format", format, 0),
OPT_FLOATRANGE("analyzeduration", analyzeduration, 0, 0, 3600),
OPT_INTRANGE("buffersize", buffersize, 0, 1, 10 * 1024 * 1024,
OPTDEF_INT(BIO_BUFFER_SIZE)),
OPT_FLAG("allow-mimetype", allow_mimetype, 0),
OPT_INTRANGE("probescore", probescore, 0, 0, 100),
OPT_STRING("cryptokey", cryptokey, 0),
OPT_CHOICE("genpts-mode", genptsmode, 0,
({"lavf", 1}, {"no", 0})),
OPT_KEYVALUELIST("o", avopts, 0),
{0}
},
.size = sizeof(struct demux_lavf_opts),
.defaults = &(const struct demux_lavf_opts){
.allow_mimetype = 1,
},
};
typedef struct lavf_priv {
char *filename;
const struct format_hack *format_hack;
AVInputFormat *avif;
AVFormatContext *avfc;
AVIOContext *pb;
int64_t last_pts;
bool init_pts;
struct sh_stream **streams; // NULL for unknown streams
int num_streams;
int cur_program;
char *mime_type;
bool merge_track_metadata;
} lavf_priv_t;
struct format_hack {
const char *ff_name;
const char *mime_type;
int probescore;
float analyzeduration;
bool max_probe; // use probescore only if max. probe size reached
};
static const struct format_hack format_hacks[] = {
// for webradios
{"aac", "audio/aacp", 25, 0.5},
{"aac", "audio/aac", 25, 0.5},
// some mp3 files don't detect correctly
{"mp3", "audio/mpeg", 24, 0.5},
{"mp3", NULL, 24, .max_probe = true},
{0}
};
static const char *const format_blacklist[] = {
"tty", // Useless non-sense, sometimes breaks MLP2 subreader.c fallback
// Image demuxers, disabled in favor of demux_mf:
"image2", "image2pipe",
"bmp_pipe", "dpx_pipe", "exr_pipe", "j2k_pipe", "png_pipe", "tiff_pipe",
"jpeg_pipe",
0
};
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_TRACE(demuxer, "%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_TRACE(demuxer, "mp_seek(%p, %"PRId64", %d)\n", stream, pos, whence);
if (whence == SEEK_END || whence == AVSEEK_SIZE) {
int64_t end;
if (stream_control(stream, STREAM_CTRL_GET_SIZE, &end) != STREAM_OK)
return -1;
if (whence == AVSEEK_SIZE)
return end;
pos += end;
} else if (whence == SEEK_CUR) {
pos += stream_tell(stream);
} else if (whence != SEEK_SET) {
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;
}
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 stream_avseek cmd = {
.stream_index = stream_idx,
.timestamp = ts,
.flags = flags,
};
if (stream_control(stream, STREAM_CTRL_AVSEEK, &cmd) == STREAM_OK) {
stream_drop_buffers(stream);
return 0;
}
return AVERROR(ENOSYS);
}
static void list_formats(struct demuxer *demuxer)
{
MP_INFO(demuxer, "Available lavf input formats:\n");
AVInputFormat *fmt = NULL;
while ((fmt = av_iformat_next(fmt)))
MP_INFO(demuxer, "%15s : %s\n", fmt->name, fmt->long_name);
}
static char *remove_prefix(char *s, const char *const *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 *const prefixes[] =
{"ffmpeg://", "lavf://", "avdevice://", "av://", NULL};
static int lavf_check_file(demuxer_t *demuxer, enum demux_check check)
{
struct MPOpts *opts = demuxer->opts;
struct demux_lavf_opts *lavfdopts = opts->demux_lavf;
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_WARN(demuxer, "Stream url is not set!\n");
}
priv->filename = remove_prefix(priv->filename, prefixes);
char *avdevice_format = NULL;
if (s->uncached_type == STREAMTYPE_AVDEVICE) {
// always require filename in the form "format:filename"
char *sep = strchr(priv->filename, ':');
if (!sep) {
MP_FATAL(demuxer, "Must specify filename in 'format:filename' form\n");
return -1;
}
avdevice_format = talloc_strndup(priv, priv->filename,
sep - priv->filename);
priv->filename = sep + 1;
}
char *mime_type = demuxer->stream->mime_type;
if (!lavfdopts->allow_mimetype || !mime_type)
mime_type = "";
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(demuxer);
return -1;
}
priv->avif = av_find_input_format(format);
if (!priv->avif) {
MP_FATAL(demuxer, "Unknown lavf format %s\n", format);
return -1;
}
MP_VERBOSE(demuxer, "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 : "",
.buf_size = 0,
.buf = av_mallocz(PROBE_BUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE),
};
if (!avpd.buf)
return -1;
bool final_probe = false;
do {
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)
final_probe = true;
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_VERBOSE(demuxer, "Found '%s' at score=%d size=%d.\n",
priv->avif->name, score, avpd.buf_size);
priv->format_hack = NULL;
for (int n = 0; format_hacks[n].ff_name; n++) {
const struct format_hack *entry = &format_hacks[n];
if (strcmp(entry->ff_name, priv->avif->name) != 0)
continue;
if (entry->mime_type && strcasecmp(entry->mime_type, mime_type) != 0)
continue;
priv->format_hack = entry;
break;
}
if (score >= min_probe)
break;
if (priv->format_hack) {
if (score >= priv->format_hack->probescore &&
(!priv->format_hack->max_probe || final_probe))
break;
}
}
priv->avif = NULL;
priv->format_hack = NULL;
} while (!final_probe);
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_VERBOSE(demuxer, "Format blacklisted.\n");
priv->avif = NULL;
break;
}
}
}
if (!priv->avif) {
MP_VERBOSE(demuxer, "No format found, try lowering probescore or forcing the format.\n");
return -1;
}
success:
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 && demux_stream_is_selected(stream) &&
!stream->attached_picture;
st->discard = selected ? AVDISCARD_DEFAULT : AVDISCARD_ALL;
}
}
static void export_replaygain(demuxer_t *demuxer, sh_audio_t *sh, AVStream *st)
{
#if HAVE_AVCODEC_REPLAYGAIN_SIDE_DATA
for (int i = 0; i < st->nb_side_data; i++) {
AVReplayGain *av_rgain;
struct replaygain_data *rgain;
AVPacketSideData *src_sd = &st->side_data[i];
if (src_sd->type != AV_PKT_DATA_REPLAYGAIN)
continue;
av_rgain = (AVReplayGain*)src_sd->data;
rgain = talloc_ptrtype(demuxer, rgain);
rgain->track_gain = (av_rgain->track_gain != INT32_MIN) ?
av_rgain->track_gain / 100000.0f : 0.0;
rgain->track_peak = (av_rgain->track_peak != 0.0) ?
av_rgain->track_peak / 100000.0f : 1.0;
rgain->album_gain = (av_rgain->album_gain != INT32_MIN) ?
av_rgain->album_gain / 100000.0f : 0.0;
rgain->album_peak = (av_rgain->album_peak != 0.0) ?
av_rgain->album_peak / 100000.0f : 1.0;
sh->replaygain_data = rgain;
}
#endif
}
// Return a dictionary entry as (decimal) integer.
static int dict_get_decimal(AVDictionary *dict, const char *entry, int def)
{
AVDictionaryEntry *e = av_dict_get(dict, entry, NULL, 0);
if (e && e->value) {
char *end = NULL;
long int r = strtol(e->value, &end, 10);
if (end && !end[0] && r >= INT_MIN && r <= INT_MAX)
return r;
}
return def;
}
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->format = codec->codec_tag;
// probably unneeded
mp_chmap_set_unknown(&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->bitrate = codec->bit_rate;
export_replaygain(demuxer, sh_audio, st);
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);
if (sh->attached_picture) {
sh->attached_picture->pts = 0;
talloc_steal(sh, sh->attached_picture);
sh->attached_picture->keyframe = true;
}
}
sh->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->bitrate = codec->bit_rate;
if (sh_video->bitrate == 0)
sh_video->bitrate = avfc->bit_rate;
#if HAVE_AV_DISPLAYMATRIX
uint8_t *sd = av_stream_get_side_data(st, AV_PKT_DATA_DISPLAYMATRIX, NULL);
if (sd)
sh_video->rotate = -av_display_rotation_get((uint32_t *)sd);
#else
int rot = dict_get_decimal(st->metadata, "rotate", -1);
if (rot >= 0)
sh_video->rotate = rot;
#endif
sh_video->rotate = ((sh_video->rotate % 360) + 360) % 360;
// This also applies to vfw-muxed mkv, but we can't detect these easily.
sh_video->avi_dts = matches_avinputformat_name(priv, "avi");
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 = talloc_size(sh, codec->extradata_size);
memcpy(sh_sub->extradata, codec->extradata, codec->extradata_size);
sh_sub->extradata_len = codec->extradata_size;
}
sh_sub->w = codec->width;
sh_sub->h = codec->height;
if (matches_avinputformat_name(priv, "microdvd")) {
AVRational r;
if (av_opt_get_q(avfc, "subfps", AV_OPT_SEARCH_CHILDREN, &r) >= 0) {
// File headers don't have a FPS set.
if (r.num < 1 || r.den < 1)
sh_sub->frame_based = av_q2d(av_inv_q(codec->time_base));
} else {
// Older libavformat versions. If the FPS matches the microdvd
// reader's default, assume it uses frame based timing.
if (codec->time_base.num == 125 && codec->time_base.den == 2997)
sh_sub->frame_based = 23.976;
}
}
break;
}
case AVMEDIA_TYPE_ATTACHMENT: {
AVDictionaryEntry *ftag = av_dict_get(st->metadata, "filename",
NULL, 0);
char *filename = ftag ? ftag->value : NULL;
char *mimetype = NULL;
switch (st->codec->codec_id) {
case AV_CODEC_ID_TTF: mimetype = "application/x-truetype-font"; break;
#if LIBAVFORMAT_VERSION_MICRO >= 100
case AV_CODEC_ID_OTF: mimetype = "application/vnd.ms-opentype"; break;
#endif
}
if (mimetype) {
demuxer_add_attachment(demuxer, bstr0(filename), bstr0(mimetype),
(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->ff_index = st->index;
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);
sh->hls_bitrate = dict_get_decimal(st->metadata, "variant_bitrate", 0);
if (!sh->title && sh->hls_bitrate > 0)
sh->title = talloc_asprintf(sh, "bitrate %d", sh->hls_bitrate);
}
select_tracks(demuxer, i);
demux_changed(demuxer, DEMUX_EVENT_STREAMS);
}
// 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 update_metadata(demuxer_t *demuxer, AVPacket *pkt)
{
#if HAVE_AVFORMAT_METADATA_UPDATE_FLAG
lavf_priv_t *priv = demuxer->priv;
if (priv->avfc->event_flags & AVFMT_EVENT_FLAG_METADATA_UPDATED) {
mp_tags_copy_from_av_dictionary(demuxer->metadata, priv->avfc->metadata);
priv->avfc->event_flags = 0;
demux_changed(demuxer, DEMUX_EVENT_METADATA);
}
if (priv->merge_track_metadata) {
for (int n = 0; n < priv->num_streams; n++) {
AVStream *st = priv->streams[n] ? priv->avfc->streams[n] : NULL;
if (st && st->event_flags & AVSTREAM_EVENT_FLAG_METADATA_UPDATED) {
mp_tags_copy_from_av_dictionary(demuxer->metadata, st->metadata);
st->event_flags = 0;
demux_changed(demuxer, DEMUX_EVENT_METADATA);
}
}
}
#elif HAVE_AVCODEC_METADATA_UPDATE_SIDE_DATA
lavf_priv_t *priv = demuxer->priv;
int md_size;
const uint8_t *md;
if (!pkt)
return;
md = av_packet_get_side_data(pkt, AV_PKT_DATA_METADATA_UPDATE, &md_size);
if (md && priv->merge_track_metadata) {
AVDictionary *dict = NULL;
av_packet_unpack_dictionary(md, md_size, &dict);
if (dict) {
mp_tags_clear(demuxer->metadata);
mp_tags_copy_from_av_dictionary(demuxer->metadata, dict);
av_dict_free(&dict);
demux_changed(demuxer, DEMUX_EVENT_METADATA);
}
}
#endif
}
static int demux_open_lavf(demuxer_t *demuxer, enum demux_check check)
{
struct MPOpts *opts = demuxer->opts;
struct demux_lavf_opts *lavfdopts = opts->demux_lavf;
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;
avfc = avformat_alloc_context();
if (!avfc)
return -1;
if (lavfdopts->cryptokey)
parse_cryptokey(avfc, lavfdopts->cryptokey);
if (lavfdopts->genptsmode)
avfc->flags |= AVFMT_FLAG_GENPTS;
if (opts->index_mode != 1)
avfc->flags |= AVFMT_FLAG_IGNIDX;
#if LIBAVFORMAT_VERSION_MICRO >= 100
/* Keep side data as side data instead of mashing it into the packet
* stream.
* Note: Libav doesn't have this horrible insanity. */
av_opt_set(avfc, "fflags", "+keepside", 0);
#endif
if (lavfdopts->probesize) {
if (av_opt_set_int(avfc, "probesize", lavfdopts->probesize, 0) < 0)
MP_ERR(demuxer, "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_ERR(demuxer, "demux_lavf, couldn't set option "
"analyzeduration to %f\n", analyze_duration);
}
AVDictionary *dopts = NULL;
if ((priv->avif->flags & AVFMT_NOFILE) ||
demuxer->stream->type == STREAMTYPE_AVDEVICE ||
matches_avinputformat_name(priv, "hls"))
{
mp_setup_av_network_options(&dopts, demuxer->global, demuxer->log, opts);
// 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;
if (stream_control(demuxer->stream, STREAM_CTRL_HAS_AVSEEK, NULL) > 0)
demuxer->seekable = true;
}
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);
}
mp_set_avdict(&dopts, lavfdopts->avopts);
if (avformat_open_input(&avfc, priv->filename, priv->avif, &dopts) < 0) {
MP_ERR(demuxer, "avformat_open_input() failed\n");
av_dict_free(&dopts);
return -1;
}
mp_avdict_print_unset(demuxer->log, MSGL_V, dopts);
av_dict_free(&dopts);
priv->avfc = avfc;
if (avformat_find_stream_info(avfc, NULL) < 0) {
MP_ERR(demuxer, "av_find_stream_info() failed\n");
return -1;
}
MP_VERBOSE(demuxer, "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];
t = av_dict_get(c->metadata, "title", NULL, 0);
int index = demuxer_add_chapter(demuxer, t ? bstr0(t->value) : bstr0(""),
c->start * av_q2d(c->time_base), i);
mp_tags_copy_from_av_dictionary(demuxer->chapters[index].metadata, c->metadata);
}
add_new_streams(demuxer);
// 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) {
priv->merge_track_metadata = true;
for (int n = 0; n < priv->num_streams; n++) {
if (priv->streams[n])
mp_tags_copy_from_av_dictionary(demuxer->metadata, avfc->streams[n]->metadata);
}
}
mp_tags_copy_from_av_dictionary(demuxer->metadata, avfc->metadata);
update_metadata(demuxer, NULL);
demuxer->ts_resets_possible = priv->avif->flags & AVFMT_TS_DISCONT;
demuxer->start_time = priv->avfc->start_time == AV_NOPTS_VALUE ?
0 : (double)priv->avfc->start_time / AV_TIME_BASE;
demuxer->allow_refresh_seeks = matches_avinputformat_name(priv, "mp4");
return 0;
}
static int demux_lavf_fill_buffer(demuxer_t *demux)
{
lavf_priv_t *priv = demux->priv;
AVPacket *pkt = &(AVPacket){0};
int r = av_read_frame(priv->avfc, pkt);
if (r < 0) {
av_free_packet(pkt);
if (r == AVERROR(EAGAIN))
return 1;
if (r == AVERROR_EOF)
return 0;
MP_WARN(demux, "error reading packet.\n");
return -1;
}
add_new_streams(demux);
update_metadata(demux, pkt);
assert(pkt->stream_index >= 0 && pkt->stream_index < priv->num_streams);
struct sh_stream *stream = priv->streams[pkt->stream_index];
AVStream *st = priv->avfc->streams[pkt->stream_index];
if (!demux_stream_is_selected(stream)) {
av_free_packet(pkt);
return 1; // don't signal EOF if skipping a packet
}
struct demux_packet *dp = new_demux_packet_from_avpacket(pkt);
if (!dp) {
av_free_packet(pkt);
return 1;
}
if (!priv->init_pts && (priv->avfc->flags & AVFMT_NOTIMESTAMPS)) {
if (pkt->pts == AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE)
pkt->dts = 0;
priv->init_pts = true;
}
if (pkt->pts != AV_NOPTS_VALUE)
dp->pts = pkt->pts * av_q2d(st->time_base);
if (pkt->dts != AV_NOPTS_VALUE)
dp->dts = pkt->dts * av_q2d(st->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 = pkt->pos;
dp->keyframe = pkt->flags & AV_PKT_FLAG_KEY;
if (dp->pts != MP_NOPTS_VALUE) {
priv->last_pts = dp->pts * AV_TIME_BASE;
} else if (dp->dts != MP_NOPTS_VALUE) {
priv->last_pts = dp->dts * AV_TIME_BASE;
}
av_free_packet(pkt);
demux_add_packet(stream, dp);
return 1;
}
static void demux_seek_lavf(demuxer_t *demuxer, double rel_seek_secs, int flags)
{
lavf_priv_t *priv = demuxer->priv;
int avsflags = 0;
priv->init_pts = false;
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;
int64_t end = 0;
stream_control(s, STREAM_CTRL_GET_SIZE, &end);
if (end > 0 && demuxer->ts_resets_possible &&
!(priv->avif->flags & AVFMT_NO_BYTE_SEEK))
{
avsflags |= AVSEEK_FLAG_BYTE;
priv->last_pts = end * 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->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_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() is designed for write-only streams, and does the wrong
// thing when reading. Flush it manually instead.
stream_drop_buffers(demuxer->stream);
priv->avfc->pb->buf_ptr = priv->avfc->pb->buf_end = priv->avfc->pb->buffer;
priv->avfc->pb->pos = stream_tell(demuxer->stream);
av_seek_frame(priv->avfc, 0, stream_tell(demuxer->stream),
AVSEEK_FLAG_BYTE);
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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