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mpv/demux/packet.h
wm4 e7e06a47a0 demux: support for some kinds of timed metadata
This makes ICY title changes show up at approximately the correct time,
even if the demuxer buffer is huge. (It'll still be wrong if the stream
byte cache contains a meaningful amount of data.)

It should have the same effect for mid-stream metadata changes in e.g.
OGG (untested).

This is still somewhat fishy, but in parts due to ICY being fishy, and
FFmpeg's metadata change API being somewhat fishy. For example, what
happens if you seek? With FFmpeg AVFMT_EVENT_FLAG_METADATA_UPDATED and
AVSTREAM_EVENT_FLAG_METADATA_UPDATED we hope that FFmpeg will correctly
restore the correct metadata when the first packet is returned.

If you seke with ICY, we're out of luck, and some audio will be
associated with the wrong tag until we get a new title through ICY
metadata update at an essentially random point (it's mostly inherent to
ICY). Then the tags will switch back and forth, and this behavior will
stick with the data stored in the demuxer cache. Fortunately, this can
happen only if the HTTP stream is actually seekable, which it usually is
not for ICY things. Seeking doesn't even make sense with ICY, since you
can't know the exact metadata location. Basically ICY metsdata sucks.

Some complexity is due to a microoptimization: I didn't want additional
atomic accesses for each packet if no timed metadata is used. (It
probably doesn't matter at all.)
2018-04-18 01:17:42 +03:00

68 lines
2.4 KiB
C

/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MPLAYER_DEMUX_PACKET_H
#define MPLAYER_DEMUX_PACKET_H
#include <stdbool.h>
#include <stddef.h>
#include <inttypes.h>
// Holds one packet/frame/whatever
typedef struct demux_packet {
int len;
unsigned char *buffer;
double pts;
double dts;
double duration;
bool keyframe;
int64_t pos; // position in source file byte stream
int stream; // source stream index
// segmentation (ordered chapters, EDL)
bool segmented;
struct mp_codec_params *codec; // set to non-NULL iff segmented is set
double start, end; // set to non-NOPTS iff segmented is set
// private
struct demux_packet *next;
struct AVPacket *avpacket; // keep the buffer allocation and sidedata
double kf_seek_pts; // demux.c internal: seek pts for keyframe range
struct mp_packet_tags *metadata; // timed metadata (demux.c internal)
} demux_packet_t;
struct AVBufferRef;
struct demux_packet *new_demux_packet(size_t len);
struct demux_packet *new_demux_packet_from_avpacket(struct AVPacket *avpkt);
struct demux_packet *new_demux_packet_from(void *data, size_t len);
struct demux_packet *new_demux_packet_from_buf(struct AVBufferRef *buf);
void demux_packet_shorten(struct demux_packet *dp, size_t len);
void free_demux_packet(struct demux_packet *dp);
struct demux_packet *demux_copy_packet(struct demux_packet *dp);
size_t demux_packet_estimate_total_size(struct demux_packet *dp);
void demux_packet_copy_attribs(struct demux_packet *dst, struct demux_packet *src);
int demux_packet_set_padding(struct demux_packet *dp, int start, int end);
int demux_packet_add_blockadditional(struct demux_packet *dp, uint64_t id,
void *data, size_t size);
#endif /* MPLAYER_DEMUX_PACKET_H */