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ffmpeg/libavformat/oggdec.c
Anton Khirnov 9200514ad8 lavf: replace AVStream.codec with AVStream.codecpar 
Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.

In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.

There are multiple important problems with this approach:
    - the fields in AVCodecContext are in general one of
        * stream parameters
        * codec options
        * codec state
      However, it's not clear which ones are which. It is consequently
      unclear which fields are a demuxer allowed to set or a muxer allowed to
      read. This leads to erratic behaviour depending on whether decoding or
      encoding is being performed or not (and whether it uses the AVStream
      embedded codec context).
    - various synchronization issues arising from the fact that the same
      context is used by several different APIs (muxers/demuxers,
      parsers, bitstream filters and encoders/decoders) simultaneously, with
      there being no clear rules for who can modify what and the different
      processes being typically delayed with respect to each other.
    - avformat_find_stream_info() making it necessary to support opening
      and closing a single codec context multiple times, thus
      complicating the semantics of freeing various allocated objects in the
      codec context.

Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
2016-02-23 17:01:58 +01:00

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/*
* Ogg bitstream support
* Luca Barbato <lu_zero@gentoo.org>
* Based on tcvp implementation
*/
/*
Copyright (C) 2005 Michael Ahlberg, Måns Rullgård
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/
#include <stdio.h>
#include "oggdec.h"
#include "avformat.h"
#include "internal.h"
#include "vorbiscomment.h"
#define MAX_PAGE_SIZE 65307
#define DECODER_BUFFER_SIZE MAX_PAGE_SIZE
static const struct ogg_codec * const ogg_codecs[] = {
&ff_skeleton_codec,
&ff_dirac_codec,
&ff_speex_codec,
&ff_vorbis_codec,
&ff_theora_codec,
&ff_flac_codec,
&ff_celt_codec,
&ff_opus_codec,
&ff_vp8_codec,
&ff_old_dirac_codec,
&ff_old_flac_codec,
&ff_ogm_video_codec,
&ff_ogm_audio_codec,
&ff_ogm_text_codec,
&ff_ogm_old_codec,
NULL
};
//FIXME We could avoid some structure duplication
static int ogg_save(AVFormatContext *s)
{
struct ogg *ogg = s->priv_data;
struct ogg_state *ost =
av_malloc(sizeof(*ost) + (ogg->nstreams - 1) * sizeof(*ogg->streams));
int i;
if (!ost)
return AVERROR(ENOMEM);
ost->pos = avio_tell(s->pb);
ost->curidx = ogg->curidx;
ost->next = ogg->state;
ost->nstreams = ogg->nstreams;
memcpy(ost->streams, ogg->streams, ogg->nstreams * sizeof(*ogg->streams));
for (i = 0; i < ogg->nstreams; i++) {
struct ogg_stream *os = ogg->streams + i;
os->buf = av_mallocz(os->bufsize + AV_INPUT_BUFFER_PADDING_SIZE);
memcpy(os->buf, ost->streams[i].buf, os->bufpos);
}
ogg->state = ost;
return 0;
}
static int ogg_restore(AVFormatContext *s, int discard)
{
struct ogg *ogg = s->priv_data;
AVIOContext *bc = s->pb;
struct ogg_state *ost = ogg->state;
int i, err;
if (!ost)
return 0;
ogg->state = ost->next;
if (!discard) {
for (i = 0; i < ogg->nstreams; i++)
av_free(ogg->streams[i].buf);
avio_seek(bc, ost->pos, SEEK_SET);
ogg->curidx = ost->curidx;
ogg->nstreams = ost->nstreams;
if ((err = av_reallocp_array(&ogg->streams, ogg->nstreams,
sizeof(*ogg->streams))) < 0) {
ogg->nstreams = 0;
return err;
} else
memcpy(ogg->streams, ost->streams,
ost->nstreams * sizeof(*ogg->streams));
}
av_free(ost);
return 0;
}
static int ogg_reset(struct ogg *ogg)
{
int i;
for (i = 0; i < ogg->nstreams; i++) {
struct ogg_stream *os = ogg->streams + i;
os->bufpos = 0;
os->pstart = 0;
os->psize = 0;
os->granule = -1;
os->lastpts = AV_NOPTS_VALUE;
os->lastdts = AV_NOPTS_VALUE;
os->sync_pos = -1;
os->page_pos = 0;
os->nsegs = 0;
os->segp = 0;
os->incomplete = 0;
}
ogg->curidx = -1;
return 0;
}
static const struct ogg_codec *ogg_find_codec(uint8_t *buf, int size)
{
int i;
for (i = 0; ogg_codecs[i]; i++)
if (size >= ogg_codecs[i]->magicsize &&
!memcmp(buf, ogg_codecs[i]->magic, ogg_codecs[i]->magicsize))
return ogg_codecs[i];
return NULL;
}
static int ogg_new_stream(AVFormatContext *s, uint32_t serial, int new_avstream)
{
struct ogg *ogg = s->priv_data;
int idx = ogg->nstreams++;
AVStream *st;
struct ogg_stream *os;
os = av_realloc(ogg->streams, ogg->nstreams * sizeof(*ogg->streams));
if (!os)
return AVERROR(ENOMEM);
ogg->streams = os;
memset(ogg->streams + idx, 0, sizeof(*ogg->streams));
os = ogg->streams + idx;
os->serial = serial;
os->bufsize = DECODER_BUFFER_SIZE;
os->buf = av_malloc(os->bufsize + AV_INPUT_BUFFER_PADDING_SIZE);
os->header = -1;
os->start_granule = OGG_NOGRANULE_VALUE;
if (new_avstream) {
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->id = idx;
avpriv_set_pts_info(st, 64, 1, 1000000);
}
return idx;
}
static int ogg_new_buf(struct ogg *ogg, int idx)
{
struct ogg_stream *os = ogg->streams + idx;
uint8_t *nb = av_malloc(os->bufsize + AV_INPUT_BUFFER_PADDING_SIZE);
int size = os->bufpos - os->pstart;
if (!nb)
return AVERROR(ENOMEM);
if (os->buf) {
memcpy(nb, os->buf + os->pstart, size);
av_free(os->buf);
}
os->buf = nb;
os->bufpos = size;
os->pstart = 0;
return 0;
}
static int ogg_read_page(AVFormatContext *s, int *str)
{
AVIOContext *bc = s->pb;
struct ogg *ogg = s->priv_data;
struct ogg_stream *os;
int ret, i = 0;
int flags, nsegs;
uint64_t gp;
uint32_t serial;
int size, idx;
uint8_t sync[4];
int sp = 0;
ret = avio_read(bc, sync, 4);
if (ret < 4)
return ret < 0 ? ret : AVERROR_EOF;
do {
int c;
if (sync[sp & 3] == 'O' &&
sync[(sp + 1) & 3] == 'g' &&
sync[(sp + 2) & 3] == 'g' && sync[(sp + 3) & 3] == 'S')
break;
c = avio_r8(bc);
if (bc->eof_reached)
return AVERROR_EOF;
sync[sp++ & 3] = c;
} while (i++ < MAX_PAGE_SIZE);
if (i >= MAX_PAGE_SIZE) {
av_log(s, AV_LOG_INFO, "cannot find sync word\n");
return AVERROR_INVALIDDATA;
}
if (avio_r8(bc) != 0) /* version */
return AVERROR_INVALIDDATA;
flags = avio_r8(bc);
gp = avio_rl64(bc);
serial = avio_rl32(bc);
avio_skip(bc, 8); /* seq, crc */
nsegs = avio_r8(bc);
idx = ogg_find_stream(ogg, serial);
if (idx < 0) {
if (ogg->headers) {
int n;
for (n = 0; n < ogg->nstreams; n++) {
av_freep(&ogg->streams[n].buf);
if (!ogg->state ||
ogg->state->streams[n].private != ogg->streams[n].private)
av_freep(&ogg->streams[n].private);
}
ogg->curidx = -1;
ogg->nstreams = 0;
idx = ogg_new_stream(s, serial, 0);
} else {
idx = ogg_new_stream(s, serial, 1);
}
if (idx < 0)
return idx;
}
os = ogg->streams + idx;
os->page_pos = avio_tell(bc) - 27;
if (os->psize > 0) {
ret = ogg_new_buf(ogg, idx);
if (ret < 0)
return ret;
}
ret = avio_read(bc, os->segments, nsegs);
if (ret < nsegs)
return ret < 0 ? ret : AVERROR_EOF;
os->nsegs = nsegs;
os->segp = 0;
size = 0;
for (i = 0; i < nsegs; i++)
size += os->segments[i];
if (flags & OGG_FLAG_CONT || os->incomplete) {
if (!os->psize) {
while (os->segp < os->nsegs) {
int seg = os->segments[os->segp++];
os->pstart += seg;
if (seg < 255)
break;
}
os->sync_pos = os->page_pos;
}
} else {
os->psize = 0;
os->sync_pos = os->page_pos;
}
if (os->bufsize - os->bufpos < size) {
uint8_t *nb = av_malloc((os->bufsize *= 2) + AV_INPUT_BUFFER_PADDING_SIZE);
if (!nb)
return AVERROR(ENOMEM);
memcpy(nb, os->buf, os->bufpos);
av_free(os->buf);
os->buf = nb;
}
ret = avio_read(bc, os->buf + os->bufpos, size);
if (ret < size)
return ret < 0 ? ret : AVERROR_EOF;
os->bufpos += size;
os->granule = gp;
os->flags = flags;
memset(os->buf + os->bufpos, 0, AV_INPUT_BUFFER_PADDING_SIZE);
if (str)
*str = idx;
return 0;
}
static int ogg_packet(AVFormatContext *s, int *str, int *dstart, int *dsize,
int64_t *fpos)
{
struct ogg *ogg = s->priv_data;
int idx, i, ret;
struct ogg_stream *os;
int complete = 0;
int segp = 0, psize = 0;
av_log(s, AV_LOG_TRACE, "ogg_packet: curidx=%i\n", ogg->curidx);
do {
idx = ogg->curidx;
while (idx < 0) {
ret = ogg_read_page(s, &idx);
if (ret < 0)
return ret;
}
os = ogg->streams + idx;
av_log(s, AV_LOG_TRACE, "ogg_packet: idx=%d pstart=%d psize=%d segp=%d nsegs=%d\n",
idx, os->pstart, os->psize, os->segp, os->nsegs);
if (!os->codec) {
if (os->header < 0) {
os->codec = ogg_find_codec(os->buf, os->bufpos);
if (!os->codec) {
av_log(s, AV_LOG_WARNING, "Codec not found\n");
os->header = 0;
return 0;
}
} else {
return 0;
}
}
segp = os->segp;
psize = os->psize;
while (os->segp < os->nsegs) {
int ss = os->segments[os->segp++];
os->psize += ss;
if (ss < 255) {
complete = 1;
break;
}
}
if (!complete && os->segp == os->nsegs) {
ogg->curidx = -1;
// Do not set incomplete for empty packets.
// Together with the code in ogg_read_page
// that discards all continuation of empty packets
// we would get an infinite loop.
os->incomplete = !!os->psize;
}
} while (!complete);
av_log(s, AV_LOG_TRACE, "ogg_packet: idx %i, frame size %i, start %i\n",
idx, os->psize, os->pstart);
if (os->granule == -1)
av_log(s, AV_LOG_WARNING,
"Page at %"PRId64" is missing granule\n",
os->page_pos);
ogg->curidx = idx;
os->incomplete = 0;
if (os->header) {
os->header = os->codec->header(s, idx);
if (!os->header) {
os->segp = segp;
os->psize = psize;
// We have reached the first non-header packet in this stream.
// Unfortunately more header packets may still follow for others,
// but if we continue with header parsing we may lose data packets.
ogg->headers = 1;
// Update the header state for all streams and
// compute the data_offset.
if (!s->internal->data_offset)
s->internal->data_offset = os->sync_pos;
for (i = 0; i < ogg->nstreams; i++) {
struct ogg_stream *cur_os = ogg->streams + i;
// if we have a partial non-header packet, its start is
// obviously at or after the data start
if (cur_os->incomplete)
s->internal->data_offset = FFMIN(s->internal->data_offset, cur_os->sync_pos);
}
} else {
os->nb_header++;
os->pstart += os->psize;
os->psize = 0;
}
} else {
os->pflags = 0;
os->pduration = 0;
if (os->codec && os->codec->packet)
os->codec->packet(s, idx);
if (str)
*str = idx;
if (dstart)
*dstart = os->pstart;
if (dsize)
*dsize = os->psize;
if (fpos)
*fpos = os->sync_pos;
os->pstart += os->psize;
os->psize = 0;
os->sync_pos = os->page_pos;
}
// determine whether there are more complete packets in this page
// if not, the page's granule will apply to this packet
os->page_end = 1;
for (i = os->segp; i < os->nsegs; i++)
if (os->segments[i] < 255) {
os->page_end = 0;
break;
}
if (os->segp == os->nsegs)
ogg->curidx = -1;
return 0;
}
static int ogg_get_headers(AVFormatContext *s)
{
struct ogg *ogg = s->priv_data;
int ret, i;
do {
ret = ogg_packet(s, NULL, NULL, NULL, NULL);
if (ret < 0)
return ret;
} while (!ogg->headers);
for (i = 0; i < ogg->nstreams; i++) {
struct ogg_stream *os = ogg->streams + i;
if (os->codec && os->codec->nb_header &&
os->nb_header < os->codec->nb_header) {
av_log(s, AV_LOG_ERROR,
"Headers mismatch for stream %d: "
"expected %d received %d.\n",
i, os->codec->nb_header, os->nb_header);
if (s->error_recognition & AV_EF_EXPLODE)
return AVERROR_INVALIDDATA;
}
if (os->start_granule != OGG_NOGRANULE_VALUE)
os->lastpts = s->streams[i]->start_time =
ogg_gptopts(s, i, os->start_granule, NULL);
}
av_log(s, AV_LOG_TRACE, "found headers\n");
return 0;
}
static int ogg_get_length(AVFormatContext *s)
{
struct ogg *ogg = s->priv_data;
int i, ret;
int64_t size, end;
if (!s->pb->seekable)
return 0;
// already set
if (s->duration != AV_NOPTS_VALUE)
return 0;
size = avio_size(s->pb);
if (size < 0)
return 0;
end = size > MAX_PAGE_SIZE ? size - MAX_PAGE_SIZE : 0;
ret = ogg_save(s);
if (ret < 0)
return ret;
avio_seek(s->pb, end, SEEK_SET);
while (!ogg_read_page(s, &i)) {
if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
ogg->streams[i].codec) {
s->streams[i]->duration =
ogg_gptopts(s, i, ogg->streams[i].granule, NULL);
if (s->streams[i]->start_time != AV_NOPTS_VALUE)
s->streams[i]->duration -= s->streams[i]->start_time;
}
}
ogg_restore(s, 0);
return 0;
}
static int ogg_read_close(AVFormatContext *s)
{
struct ogg *ogg = s->priv_data;
int i;
for (i = 0; i < ogg->nstreams; i++) {
av_free(ogg->streams[i].buf);
if (ogg->streams[i].codec &&
ogg->streams[i].codec->cleanup) {
ogg->streams[i].codec->cleanup(s, i);
}
av_free(ogg->streams[i].private);
}
av_free(ogg->streams);
return 0;
}
static int ogg_read_header(AVFormatContext *s)
{
struct ogg *ogg = s->priv_data;
int ret, i;
ogg->curidx = -1;
//linear headers seek from start
ret = ogg_get_headers(s);
if (ret < 0) {
ogg_read_close(s);
return ret;
}
for (i = 0; i < ogg->nstreams; i++)
if (ogg->streams[i].header < 0)
ogg->streams[i].codec = NULL;
//linear granulepos seek from end
ret = ogg_get_length(s);
if (ret < 0) {
ogg_read_close(s);
return ret;
}
//fill the extradata in the per codec callbacks
return 0;
}
static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + idx;
int64_t pts = AV_NOPTS_VALUE;
if (dts)
*dts = AV_NOPTS_VALUE;
if (os->lastpts != AV_NOPTS_VALUE) {
pts = os->lastpts;
os->lastpts = AV_NOPTS_VALUE;
}
if (os->lastdts != AV_NOPTS_VALUE) {
if (dts)
*dts = os->lastdts;
os->lastdts = AV_NOPTS_VALUE;
}
if (os->page_end) {
if (os->granule != -1LL) {
if (os->codec && os->codec->granule_is_start)
pts = ogg_gptopts(s, idx, os->granule, dts);
else
os->lastpts = ogg_gptopts(s, idx, os->granule, &os->lastdts);
os->granule = -1LL;
}
}
return pts;
}
static int ogg_read_packet(AVFormatContext *s, AVPacket *pkt)
{
struct ogg *ogg;
struct ogg_stream *os;
int idx = -1, ret;
int pstart, psize;
int64_t fpos, pts, dts;
//Get an ogg packet
retry:
do {
ret = ogg_packet(s, &idx, &pstart, &psize, &fpos);
if (ret < 0)
return ret;
} while (idx < 0 || !s->streams[idx]);
ogg = s->priv_data;
os = ogg->streams + idx;
// pflags might not be set until after this
pts = ogg_calc_pts(s, idx, &dts);
if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
goto retry;
os->keyframe_seek = 0;
//Alloc a pkt
ret = av_new_packet(pkt, psize);
if (ret < 0)
return ret;
pkt->stream_index = idx;
memcpy(pkt->data, os->buf + pstart, psize);
pkt->pts = pts;
pkt->dts = dts;
pkt->flags = os->pflags;
pkt->duration = os->pduration;
pkt->pos = fpos;
return psize;
}
static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
int64_t *pos_arg, int64_t pos_limit)
{
struct ogg *ogg = s->priv_data;
AVIOContext *bc = s->pb;
int64_t pts = AV_NOPTS_VALUE;
int i = -1;
avio_seek(bc, *pos_arg, SEEK_SET);
ogg_reset(ogg);
while (avio_tell(bc) < pos_limit &&
!ogg_packet(s, &i, NULL, NULL, pos_arg)) {
if (i == stream_index) {
struct ogg_stream *os = ogg->streams + stream_index;
pts = ogg_calc_pts(s, i, NULL);
if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
pts = AV_NOPTS_VALUE;
}
if (pts != AV_NOPTS_VALUE)
break;
}
ogg_reset(ogg);
return pts;
}
static int ogg_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + stream_index;
int ret;
// Try seeking to a keyframe first. If this fails (very possible),
// av_seek_frame will fall back to ignoring keyframes
if (s->streams[stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO
&& !(flags & AVSEEK_FLAG_ANY))
os->keyframe_seek = 1;
ret = ff_seek_frame_binary(s, stream_index, timestamp, flags);
os = ogg->streams + stream_index;
if (ret < 0)
os->keyframe_seek = 0;
return ret;
}
static int ogg_probe(AVProbeData *p)
{
if (!memcmp("OggS", p->buf, 5) && p->buf[5] <= 0x7)
return AVPROBE_SCORE_MAX;
return 0;
}
AVInputFormat ff_ogg_demuxer = {
.name = "ogg",
.long_name = NULL_IF_CONFIG_SMALL("Ogg"),
.priv_data_size = sizeof(struct ogg),
.read_probe = ogg_probe,
.read_header = ogg_read_header,
.read_packet = ogg_read_packet,
.read_close = ogg_read_close,
.read_seek = ogg_read_seek,
.read_timestamp = ogg_read_timestamp,
.extensions = "ogg",
.flags = AVFMT_GENERIC_INDEX | AVFMT_NOBINSEARCH,
};
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