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/*
* AVI decoder.
* Copyright (c) 2001 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avformat.h"
#include "avi.h"
//#define DEBUG
typedef struct AVIIndex {
unsigned char tag[4];
unsigned int flags, pos, len;
struct AVIIndex *next;
} AVIIndex;
typedef struct {
int64_t movi_end;
offset_t movi_list;
AVIIndex *first, *last;
} AVIContext;
#ifdef DEBUG
static void print_tag(const char *str, unsigned int tag, int size)
{
printf("%s: tag=%c%c%c%c size=0x%x\n",
str, tag & 0xff,
(tag >> 8) & 0xff,
(tag >> 16) & 0xff,
(tag >> 24) & 0xff,
size);
}
#endif
static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
AVIContext *avi = s->priv_data;
ByteIOContext *pb = &s->pb;
uint32_t tag, tag1;
int codec_type, stream_index, frame_period, bit_rate;
unsigned int size;
int i;
AVStream *st;
/* check RIFF header */
tag = get_le32(pb);
if (tag != MKTAG('R', 'I', 'F', 'F'))
return -1;
get_le32(pb); /* file size */
tag = get_le32(pb);
if (tag != MKTAG('A', 'V', 'I', ' '))
return -1;
/* first list tag */
stream_index = -1;
codec_type = -1;
frame_period = 0;
for(;;) {
if (url_feof(pb))
goto fail;
tag = get_le32(pb);
size = get_le32(pb);
#ifdef DEBUG
print_tag("tag", tag, size);
#endif
switch(tag) {
case MKTAG('L', 'I', 'S', 'T'):
/* ignored, except when start of video packets */
tag1 = get_le32(pb);
#ifdef DEBUG
print_tag("list", tag1, 0);
#endif
if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
avi->movi_end = url_ftell(pb) + size - 4;
#ifdef DEBUG
printf("movi end=%Lx\n", avi->movi_end);
#endif
goto end_of_header;
}
break;
case MKTAG('a', 'v', 'i', 'h'):
/* avi header */
/* using frame_period is bad idea */
frame_period = get_le32(pb);
bit_rate = get_le32(pb) * 8;
url_fskip(pb, 4 * 4);
s->nb_streams = get_le32(pb);
for(i=0;i<s->nb_streams;i++) {
AVStream *st = av_mallocz(sizeof(AVStream));
if (!st)
goto fail;
avcodec_get_context_defaults(&st->codec);
s->streams[i] = st;
}
url_fskip(pb, size - 7 * 4);
break;
case MKTAG('s', 't', 'r', 'h'):
/* stream header */
stream_index++;
tag1 = get_le32(pb);
switch(tag1) {
case MKTAG('v', 'i', 'd', 's'):
codec_type = CODEC_TYPE_VIDEO;
get_le32(pb); /* codec tag */
get_le32(pb); /* flags */
get_le16(pb); /* priority */
get_le16(pb); /* language */
get_le32(pb); /* XXX: initial frame ? */
get_le32(pb); /* scale */
get_le32(pb); /* rate */
url_fskip(pb, size - 7 * 4);
break;
case MKTAG('a', 'u', 'd', 's'):
codec_type = CODEC_TYPE_AUDIO;
/* nothing really useful */
url_fskip(pb, size - 4);
break;
default:
goto fail;
}
break;
case MKTAG('s', 't', 'r', 'f'):
/* stream header */
if (stream_index >= s->nb_streams) {
url_fskip(pb, size);
} else {
st = s->streams[stream_index];
switch(codec_type) {
case CODEC_TYPE_VIDEO:
get_le32(pb); /* size */
st->codec.width = get_le32(pb);
st->codec.height = get_le32(pb);
if (frame_period)
st->codec.frame_rate = (int64_t_C(1000000) * FRAME_RATE_BASE) / frame_period;
else
st->codec.frame_rate = 25 * FRAME_RATE_BASE;
get_le16(pb); /* panes */
get_le16(pb); /* depth */
tag1 = get_le32(pb);
#ifdef DEBUG
print_tag("video", tag1, 0);
#endif
st->codec.codec_type = CODEC_TYPE_VIDEO;
st->codec.codec_tag = tag1;
st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
url_fskip(pb, size - 5 * 4);
break;
case CODEC_TYPE_AUDIO:
get_wav_header(pb, &st->codec, (size >= 18));
if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
url_fskip(pb, 1);
break;
default:
url_fskip(pb, size);
break;
}
}
break;
default:
/* skip tag */
size += (size & 1);
url_fskip(pb, size);
break;
}
}
end_of_header:
/* check stream number */
if (stream_index != s->nb_streams - 1) {
fail:
for(i=0;i<s->nb_streams;i++) {
av_freep(&s->streams[i]);
}
return -1;
}
return 0;
}
static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIContext *avi = s->priv_data;
ByteIOContext *pb = &s->pb;
int n, d1, d2, size;
find_next:
if (url_feof(pb) || url_ftell(pb) >= avi->movi_end)
return -1;
d1 = get_byte(pb);
if (d1 < '0' || d1 > '9')
goto find_next;
d2 = get_byte(pb);
if (d2 < '0' || d2 > '9')
goto find_next;
n = (d1 - '0') * 10 + (d2 - '0');
if (n < 0 || n >= s->nb_streams)
goto find_next;
d1 = get_byte(pb);
d2 = get_byte(pb);
if ((d1 != 'd' && d2 != 'c') &&
(d1 != 'w' && d2 != 'b'))
goto find_next;
size = get_le32(pb);
av_new_packet(pkt, size);
pkt->stream_index = n;
get_buffer(pb, pkt->data, pkt->size);
if (size & 1)
get_byte(pb);
return 0;
}
static int avi_read_close(AVFormatContext *s)
{
return 0;
}
static int avi_probe(AVProbeData *p)
{
/* check file header */
if (p->buf_size <= 32)
return 0;
if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
p->buf[2] == 'F' && p->buf[3] == 'F' &&
p->buf[8] == 'A' && p->buf[9] == 'V' &&
p->buf[10] == 'I' && p->buf[11] == ' ')
return AVPROBE_SCORE_MAX;
else
return 0;
}
static AVInputFormat avi_iformat = {
"avi",
"avi format",
sizeof(AVIContext),
avi_probe,
avi_read_header,
avi_read_packet,
avi_read_close,
};
int avidec_init(void)
{
av_register_input_format(&avi_iformat);
return 0;
}
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