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libavformat
tiertexseq.c
Go to the documentation of this file.
1
/*
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* Tiertex Limited SEQ File Demuxer
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* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
9
* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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27
#include "
avformat.h
"
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#include "
internal.h
"
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30
#define SEQ_FRAME_SIZE 6144
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#define SEQ_FRAME_W 256
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#define SEQ_FRAME_H 128
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#define SEQ_NUM_FRAME_BUFFERS 30
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#define SEQ_AUDIO_BUFFER_SIZE 882
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#define SEQ_SAMPLE_RATE 22050
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#define SEQ_FRAME_RATE 25
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38
39
typedef
struct
TiertexSeqFrameBuffer
{
40
int
fill_size
;
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int
data_size
;
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unsigned
char
*
data
;
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}
TiertexSeqFrameBuffer
;
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45
typedef
struct
SeqDemuxContext
{
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int
audio_stream_index
;
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int
video_stream_index
;
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int
current_frame_pts
;
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int
current_frame_offs
;
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TiertexSeqFrameBuffer
frame_buffers
[
SEQ_NUM_FRAME_BUFFERS
];
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int
frame_buffers_count
;
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unsigned
int
current_audio_data_size
;
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unsigned
int
current_audio_data_offs
;
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unsigned
int
current_pal_data_size
;
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unsigned
int
current_pal_data_offs
;
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unsigned
int
current_video_data_size
;
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unsigned
char
*
current_video_data_ptr
;
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int
audio_buffer_full
;
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}
SeqDemuxContext
;
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static
int
seq_probe
(
AVProbeData
*p)
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{
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int
i;
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if
(p->
buf_size
< 258)
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return
0;
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/* there's no real header in a .seq file, the only thing they have in common */
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/* is the first 256 bytes of the file which are always filled with 0 */
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for
(i = 0; i < 256; i++)
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if
(p->
buf
[i])
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return
0;
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if
(p->
buf
[256]==0 && p->
buf
[257]==0)
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return
0;
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/* only one fourth of the score since the previous check is too naive */
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return
AVPROBE_SCORE_MAX
/ 4;
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}
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static
int
seq_init_frame_buffers
(
SeqDemuxContext
*seq,
AVIOContext
*pb)
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{
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int
i, sz;
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TiertexSeqFrameBuffer
*seq_buffer;
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avio_seek
(pb, 256, SEEK_SET);
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for
(i = 0; i <
SEQ_NUM_FRAME_BUFFERS
; i++) {
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sz =
avio_rl16
(pb);
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if
(sz == 0)
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break
;
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else
{
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seq_buffer = &seq->
frame_buffers
[i];
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seq_buffer->
fill_size
= 0;
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seq_buffer->
data_size
= sz;
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seq_buffer->
data
=
av_malloc
(sz);
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if
(!seq_buffer->
data
)
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return
AVERROR
(ENOMEM);
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}
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}
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seq->
frame_buffers_count
= i;
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return
0;
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}
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static
int
seq_fill_buffer
(
SeqDemuxContext
*seq,
AVIOContext
*pb,
int
buffer_num,
unsigned
int
data_offs,
int
data_size)
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{
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TiertexSeqFrameBuffer
*seq_buffer;
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if
(buffer_num >=
SEQ_NUM_FRAME_BUFFERS
)
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return
AVERROR_INVALIDDATA
;
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seq_buffer = &seq->
frame_buffers
[buffer_num];
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if
(seq_buffer->
fill_size
+ data_size > seq_buffer->
data_size
|| data_size <= 0)
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return
AVERROR_INVALIDDATA
;
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avio_seek
(pb, seq->
current_frame_offs
+ data_offs, SEEK_SET);
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if
(
avio_read
(pb, seq_buffer->
data
+ seq_buffer->
fill_size
, data_size) != data_size)
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return
AVERROR
(EIO);
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seq_buffer->
fill_size
+= data_size;
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return
0;
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}
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static
int
seq_parse_frame_data
(
SeqDemuxContext
*seq,
AVIOContext
*pb)
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{
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unsigned
int
offset_table
[4], buffer_num[4];
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TiertexSeqFrameBuffer
*seq_buffer;
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int
i, e, err;
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seq->
current_frame_offs
+=
SEQ_FRAME_SIZE
;
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avio_seek
(pb, seq->
current_frame_offs
, SEEK_SET);
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/* sound data */
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seq->
current_audio_data_offs
=
avio_rl16
(pb);
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if
(seq->
current_audio_data_offs
) {
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seq->
current_audio_data_size
=
SEQ_AUDIO_BUFFER_SIZE
* 2;
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}
else
{
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seq->
current_audio_data_size
= 0;
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}
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/* palette data */
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seq->
current_pal_data_offs
=
avio_rl16
(pb);
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if
(seq->
current_pal_data_offs
) {
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seq->
current_pal_data_size
= 768;
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}
else
{
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seq->
current_pal_data_size
= 0;
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}
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/* video data */
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for
(i = 0; i < 4; i++)
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buffer_num[i] =
avio_r8
(pb);
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for
(i = 0; i < 4; i++)
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offset_table[i] =
avio_rl16
(pb);
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for
(i = 0; i < 3; i++) {
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if
(offset_table[i]) {
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for
(e = i + 1; e < 3 && offset_table[e] == 0; e++);
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err =
seq_fill_buffer
(seq, pb, buffer_num[1 + i],
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offset_table[i],
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offset_table[e] - offset_table[i]);
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if
(err)
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return
err;
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}
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}
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168
if
(buffer_num[0] != 255) {
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if
(buffer_num[0] >=
SEQ_NUM_FRAME_BUFFERS
)
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return
AVERROR_INVALIDDATA
;
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seq_buffer = &seq->
frame_buffers
[buffer_num[0]];
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seq->
current_video_data_size
= seq_buffer->
fill_size
;
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seq->
current_video_data_ptr
= seq_buffer->
data
;
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seq_buffer->
fill_size
= 0;
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}
else
{
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seq->
current_video_data_size
= 0;
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seq->
current_video_data_ptr
= 0;
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}
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return
0;
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}
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184
static
int
seq_read_header
(
AVFormatContext
*s,
AVFormatParameters
*ap)
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{
186
int
i, rc;
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SeqDemuxContext
*seq = s->
priv_data
;
188
AVIOContext
*pb = s->
pb
;
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AVStream
*st;
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/* init internal buffers */
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rc =
seq_init_frame_buffers
(seq, pb);
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if
(rc)
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return
rc;
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seq->
current_frame_offs
= 0;
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/* preload (no audio data, just buffer operations related data) */
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for
(i = 1; i <= 100; i++) {
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rc =
seq_parse_frame_data
(seq, pb);
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if
(rc)
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return
rc;
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}
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seq->
current_frame_pts
= 0;
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seq->
audio_buffer_full
= 0;
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/* initialize the video decoder stream */
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st =
avformat_new_stream
(s,
NULL
);
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if
(!st)
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return
AVERROR
(ENOMEM);
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avpriv_set_pts_info
(st, 32, 1,
SEQ_FRAME_RATE
);
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seq->
video_stream_index
= st->
index
;
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st->
codec
->
codec_type
=
AVMEDIA_TYPE_VIDEO
;
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st->
codec
->
codec_id
=
CODEC_ID_TIERTEXSEQVIDEO
;
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st->
codec
->
codec_tag
= 0;
/* no fourcc */
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st->
codec
->
width
=
SEQ_FRAME_W
;
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st->
codec
->
height
=
SEQ_FRAME_H
;
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/* initialize the audio decoder stream */
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st =
avformat_new_stream
(s,
NULL
);
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if
(!st)
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return
AVERROR
(ENOMEM);
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avpriv_set_pts_info
(st, 32, 1,
SEQ_SAMPLE_RATE
);
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seq->
audio_stream_index
= st->
index
;
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st->
codec
->
codec_type
=
AVMEDIA_TYPE_AUDIO
;
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st->
codec
->
codec_id
=
CODEC_ID_PCM_S16BE
;
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st->
codec
->
codec_tag
= 0;
/* no tag */
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st->
codec
->
channels
= 1;
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st->
codec
->
sample_rate
=
SEQ_SAMPLE_RATE
;
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st->
codec
->
bits_per_coded_sample
= 16;
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st->
codec
->
bit_rate
= st->
codec
->
sample_rate
* st->
codec
->
bits_per_coded_sample
* st->
codec
->
channels
;
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st->
codec
->
block_align
= st->
codec
->
channels
* st->
codec
->
bits_per_coded_sample
;
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return
0;
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}
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static
int
seq_read_packet
(
AVFormatContext
*s,
AVPacket
*pkt)
242
{
243
int
rc;
244
SeqDemuxContext
*seq = s->
priv_data
;
245
AVIOContext
*pb = s->
pb
;
246
247
if
(!seq->
audio_buffer_full
) {
248
rc =
seq_parse_frame_data
(seq, pb);
249
if
(rc)
250
return
rc;
251
252
/* video packet */
253
if
(seq->
current_pal_data_size
+ seq->
current_video_data_size
!= 0) {
254
if
(
av_new_packet
(pkt, 1 + seq->
current_pal_data_size
+ seq->
current_video_data_size
))
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return
AVERROR
(ENOMEM);
256
257
pkt->
data
[0] = 0;
258
if
(seq->
current_pal_data_size
) {
259
pkt->
data
[0] |= 1;
260
avio_seek
(pb, seq->
current_frame_offs
+ seq->
current_pal_data_offs
, SEEK_SET);
261
if
(
avio_read
(pb, &pkt->
data
[1], seq->
current_pal_data_size
) != seq->
current_pal_data_size
)
262
return
AVERROR
(EIO);
263
}
264
if
(seq->
current_video_data_size
) {
265
pkt->
data
[0] |= 2;
266
memcpy(&pkt->
data
[1 + seq->
current_pal_data_size
],
267
seq->
current_video_data_ptr
,
268
seq->
current_video_data_size
);
269
}
270
pkt->
stream_index
= seq->
video_stream_index
;
271
pkt->
pts
= seq->
current_frame_pts
;
272
273
/* sound buffer will be processed on next read_packet() call */
274
seq->
audio_buffer_full
= 1;
275
return
0;
276
}
277
}
278
279
/* audio packet */
280
if
(seq->
current_audio_data_offs
== 0)
/* end of data reached */
281
return
AVERROR
(EIO);
282
283
avio_seek
(pb, seq->
current_frame_offs
+ seq->
current_audio_data_offs
, SEEK_SET);
284
rc =
av_get_packet
(pb, pkt, seq->
current_audio_data_size
);
285
if
(rc < 0)
286
return
rc;
287
288
pkt->
stream_index
= seq->
audio_stream_index
;
289
seq->
current_frame_pts
++;
290
291
seq->
audio_buffer_full
= 0;
292
return
0;
293
}
294
295
static
int
seq_read_close
(
AVFormatContext
*s)
296
{
297
int
i;
298
SeqDemuxContext
*seq = s->
priv_data
;
299
300
for
(i = 0; i <
SEQ_NUM_FRAME_BUFFERS
; i++)
301
av_free
(seq->
frame_buffers
[i].
data
);
302
303
return
0;
304
}
305
306
AVInputFormat
ff_tiertexseq_demuxer
= {
307
.
name
=
"tiertexseq"
,
308
.long_name =
NULL_IF_CONFIG_SMALL
(
"Tiertex Limited SEQ format"
),
309
.priv_data_size =
sizeof
(
SeqDemuxContext
),
310
.
read_probe
=
seq_probe
,
311
.
read_header
=
seq_read_header
,
312
.
read_packet
=
seq_read_packet
,
313
.
read_close
=
seq_read_close
,
314
};