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avidec: demux ASS and SRT tracks out of GAB2 chunks 

Originally committed as revision 24579 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Aurelien Jacobs 2010-07-29 22:17:30 +00:00
parent ac066b83e9
commit 37287d41f4
1 changed files with 123 additions and 2 deletions
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125
libavformat/avidec.c
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@ -24,6 +24,7 @@
#include "libavutil/intreadwrite.h"
#include "libavutil/bswap.h"
#include "libavcodec/bytestream.h"
#include "avformat.h"
#include "avi.h"
#include "dv.h"
@ -49,6 +50,10 @@ typedef struct AVIStream {
uint32_t pal[256];
int has_pal;
int dshow_block_align; ///< block align variable used to emulate bugs in the MS dshow demuxer
AVFormatContext *sub_ctx;
AVPacket sub_pkt;
uint8_t *sub_buffer;
} AVIStream;
typedef struct {
@ -467,8 +472,7 @@ static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
codec_type = AVMEDIA_TYPE_AUDIO;
break;
case MKTAG('t', 'x', 't', 's'):
//FIXME
codec_type = AVMEDIA_TYPE_DATA; //AVMEDIA_TYPE_SUB ? FIXME
codec_type = AVMEDIA_TYPE_SUBTITLE;
break;
case MKTAG('d', 'a', 't', 's'):
codec_type = AVMEDIA_TYPE_DATA;
@ -599,6 +603,10 @@ static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
ast->dshow_block_align = 0;
}
break;
case AVMEDIA_TYPE_SUBTITLE:
st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codec->codec_id = CODEC_ID_PROBE;
break;
default:
st->codec->codec_type = AVMEDIA_TYPE_DATA;
st->codec->codec_id= CODEC_ID_NONE;
@ -688,6 +696,88 @@ static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
return 0;
}
static int read_gab2_sub(AVStream *st, AVPacket *pkt) {
if (!strcmp(pkt->data, "GAB2") && AV_RL16(pkt->data+5) == 2) {
uint8_t desc[256], *d = desc;
uint8_t *end, *ptr = pkt->data+7;
unsigned int size, desc_len = bytestream_get_le32(&ptr);
int score = AVPROBE_SCORE_MAX / 2;
AVIStream *ast = st->priv_data;
AVInputFormat *sub_demuxer;
AVRational time_base;
ByteIOContext *pb;
AVProbeData pd;
if (desc_len > FFMAX(pkt->size-17, 0))
return 0;
end = ptr + desc_len;
while (ptr < end-1) {
uint8_t tmp;
uint32_t ch;
GET_UTF16(ch, ptr < end-1 ? bytestream_get_le16(&ptr) : 0, break;);
PUT_UTF8(ch, tmp, if(d-desc < sizeof(desc)-1) *d++ = tmp;);
}
*d = 0;
if (*desc)
av_metadata_set2(&st->metadata, "title", desc, 0);
ptr = end + 2;
size = bytestream_get_le32(&ptr);
size = FFMIN(size, pkt->size+pkt->data-ptr);
pd = (AVProbeData) { .buf = ptr, .buf_size = size };
if (!(sub_demuxer = av_probe_input_format2(&pd, 1, &score)))
return 0;
pb = av_alloc_put_byte(ptr, size, 0, NULL, NULL, NULL, NULL);
if (!av_open_input_stream(&ast->sub_ctx, pb, "", sub_demuxer, NULL)) {
av_read_packet(ast->sub_ctx, &ast->sub_pkt);
*st->codec = *ast->sub_ctx->streams[0]->codec;
ast->sub_ctx->streams[0]->codec->extradata = NULL;
time_base = ast->sub_ctx->streams[0]->time_base;
av_set_pts_info(st, 64, time_base.num, time_base.den);
}
ast->sub_buffer = pkt->data;
memset(pkt, 0, sizeof(*pkt));
return 1;
}
return 0;
}
static AVStream *get_subtitle_pkt(AVFormatContext *s, AVStream *next_st,
AVPacket *pkt)
{
AVIStream *ast, *next_ast = next_st->priv_data;
int64_t ts, next_ts, ts_min = INT64_MAX;
AVStream *st, *sub_st = NULL;
int i;
next_ts = av_rescale_q(next_ast->frame_offset, next_st->time_base,
AV_TIME_BASE_Q);
for (i=0; i<s->nb_streams; i++) {
st = s->streams[i];
ast = st->priv_data;
if (st->discard < AVDISCARD_ALL && ast->sub_pkt.data) {
ts = av_rescale_q(ast->sub_pkt.dts, st->time_base, AV_TIME_BASE_Q);
if (ts <= next_ts && ts < ts_min) {
ts_min = ts;
sub_st = st;
}
}
}
if (sub_st) {
ast = sub_st->priv_data;
*pkt = ast->sub_pkt;
pkt->stream_index = sub_st->index;
if (av_read_packet(ast->sub_ctx, &ast->sub_pkt) < 0)
ast->sub_pkt.data = NULL;
}
return sub_st;
}
static int get_stream_idx(int *d){
if( d[0] >= '0' && d[0] <= '9'
&& d[1] >= '0' && d[1] <= '9'){
@ -776,6 +866,9 @@ resync:
AVIStream *ast= st->priv_data;
int size, err;
if(get_subtitle_pkt(s, st, pkt))
return 0;
if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
size= INT_MAX;
else if(ast->sample_size < 32)
@ -810,6 +903,12 @@ resync:
pkt->flags |= AV_PKT_FLAG_KEY;
if (size < 0)
av_free_packet(pkt);
} else if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
&& !st->codec->codec_tag && read_gab2_sub(st, pkt)) {
ast->frame_offset++;
avi->stream_index = -1;
ast->remaining = 0;
goto resync;
} else {
/* XXX: How to handle B-frames in AVI? */
pkt->dts = ast->frame_offset;
@ -1092,6 +1191,16 @@ static int avi_load_index(AVFormatContext *s)
return ret;
}
static void seek_subtitle(AVStream *st, AVStream *st2, int64_t timestamp)
{
AVIStream *ast2 = st2->priv_data;
int64_t ts2 = av_rescale_q(timestamp, st->time_base, st2->time_base);
av_free_packet(&ast2->sub_pkt);
if (avformat_seek_file(ast2->sub_ctx, 0, INT64_MIN, ts2, ts2, 0) >= 0 ||
avformat_seek_file(ast2->sub_ctx, 0, ts2, ts2, INT64_MAX, 0) >= 0)
av_read_packet(ast2->sub_ctx, &ast2->sub_pkt);
}
static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
AVIContext *avi = s->priv_data;
@ -1141,6 +1250,11 @@ static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
ast2->packet_size=
ast2->remaining= 0;
if (ast2->sub_ctx) {
seek_subtitle(st, st2, timestamp);
continue;
}
if (st2->nb_index_entries <= 0)
continue;
@ -1178,7 +1292,14 @@ static int avi_read_close(AVFormatContext *s)
for(i=0;i<s->nb_streams;i++) {
AVStream *st = s->streams[i];
AVIStream *ast = st->priv_data;
av_free(st->codec->palctrl);
if (ast->sub_ctx) {
av_freep(ast->sub_ctx->pb);
av_close_input_stream(ast->sub_ctx);
}
av_free(ast->sub_buffer);
av_free_packet(&ast->sub_pkt);
}
if (avi->dv_demux)