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FFmpeg/libavformat/avidec.c

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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"
#include "dv.h"
//#define DEBUG
typedef struct AVIIndex {
unsigned char tag[4];
unsigned int flags, pos, len;
struct AVIIndex *next;
} AVIIndex;
typedef struct {
int64_t riff_end;
int64_t movi_end;
offset_t movi_list;
AVIIndex *first, *last;
void* dv_demux;
} 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 get_riff(AVIContext *avi, ByteIOContext *pb)
{
uint32_t tag;
/* check RIFF header */
tag = get_le32(pb);
if (tag != MKTAG('R', 'I', 'F', 'F'))
return -1;
avi->riff_end = get_le32(pb); /* RIFF chunk size */
avi->riff_end += url_ftell(pb); /* RIFF chunk end */
tag = get_le32(pb);
if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
return -1;
return 0;
}
static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
AVIContext *avi = s->priv_data;
ByteIOContext *pb = &s->pb;
uint32_t tag, tag1, handler;
int codec_type, stream_index, frame_period, bit_rate, scale, rate;
unsigned int size, nb_frames;
int i, n;
AVStream *st;
int xan_video = 0; /* hack to support Xan A/V */
if (get_riff(avi, pb) < 0)
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);
n = get_le32(pb);
for(i=0;i<n;i++) {
st = av_new_stream(s, i);
if (!st)
goto fail;
}
url_fskip(pb, size - 7 * 4);
break;
case MKTAG('s', 't', 'r', 'h'):
/* stream header */
stream_index++;
tag1 = get_le32(pb);
handler = get_le32(pb); /* codec tag */
switch(tag1) {
case MKTAG('i', 'a', 'v', 's'):
case MKTAG('i', 'v', 'a', 's'):
/*
* After some consideration -- I don't think we
* have to support anything but DV in a type1 AVIs.
*/
if (s->nb_streams != 1)
goto fail;
if (handler != MKTAG('d', 'v', 's', 'd') &&
handler != MKTAG('d', 'v', 'h', 'd') &&
handler != MKTAG('d', 'v', 's', 'l'))
goto fail;
avi->dv_demux = dv_init_demux(s, stream_index, stream_index + 1);
if (!avi->dv_demux)
goto fail;
stream_index++;
case MKTAG('v', 'i', 'd', 's'):
codec_type = CODEC_TYPE_VIDEO;
if (stream_index >= s->nb_streams) {
url_fskip(pb, size - 8);
break;
}
st = s->streams[stream_index];
get_le32(pb); /* flags */
get_le16(pb); /* priority */
get_le16(pb); /* language */
get_le32(pb); /* XXX: initial frame ? */
scale = get_le32(pb); /* scale */
rate = get_le32(pb); /* rate */
if(scale && rate){
st->codec.frame_rate = rate;
st->codec.frame_rate_base = scale;
}else if(frame_period){
st->codec.frame_rate = 1000000;
st->codec.frame_rate_base = frame_period;
}else{
st->codec.frame_rate = 25;
st->codec.frame_rate_base = 1;
}
get_le32(pb); /* start */
nb_frames = get_le32(pb);
st->start_time = 0;
st->duration = (double)nb_frames *
st->codec.frame_rate_base * AV_TIME_BASE /
st->codec.frame_rate;
url_fskip(pb, size - 9 * 4);
break;
case MKTAG('a', 'u', 'd', 's'):
{
unsigned int length, rate;
codec_type = CODEC_TYPE_AUDIO;
if (stream_index >= s->nb_streams) {
url_fskip(pb, size - 8);
break;
}
st = s->streams[stream_index];
get_le32(pb); /* flags */
get_le16(pb); /* priority */
get_le16(pb); /* language */
get_le32(pb); /* initial frame */
get_le32(pb); /* scale */
rate = get_le32(pb);
get_le32(pb); /* start */
length = get_le32(pb); /* length, in samples or bytes */
st->start_time = 0;
if (rate != 0)
st->duration = (int64_t)length * AV_TIME_BASE / rate;
url_fskip(pb, size - 9 * 4);
}
break;
default:
goto fail;
}
break;
case MKTAG('s', 't', 'r', 'f'):
/* stream header */
if (stream_index >= s->nb_streams || avi->dv_demux) {
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);
get_le16(pb); /* panes */
st->codec.bits_per_sample= get_le16(pb); /* depth */
tag1 = get_le32(pb);
get_le32(pb); /* ImageSize */
get_le32(pb); /* XPelsPerMeter */
get_le32(pb); /* YPelsPerMeter */
get_le32(pb); /* ClrUsed */
get_le32(pb); /* ClrImportant */
st->codec.extradata_size= size - 10*4;
st->codec.extradata= av_malloc(st->codec.extradata_size);
get_buffer(pb, st->codec.extradata, st->codec.extradata_size);
if(st->codec.extradata_size & 1) //FIXME check if the encoder really did this correctly
get_byte(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);
if (st->codec.codec_id == CODEC_ID_XAN_WC4)
xan_video = 1;
// url_fskip(pb, size - 5 * 4);
break;
case CODEC_TYPE_AUDIO:
get_wav_header(pb, &st->codec, size);
if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
url_fskip(pb, 1);
/* special case time: To support Xan DPCM, hardcode
* the format if Xxan is the video codec */
if (xan_video)
st->codec.codec_id = CODEC_ID_XAN_DPCM;
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]->codec.extradata);
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, d[8], size, i;
void* dstr;
memset(d, -1, sizeof(int)*8);
if (avi->dv_demux) {
size = dv_get_packet(avi->dv_demux, pkt);
if (size >= 0)
return size;
}
for(i=url_ftell(pb); !url_feof(pb); i++) {
int j;
if (i >= avi->movi_end) { /* Let's see if it's an OpenDML AVI */
uint32_t tag, size, tag2;
url_fskip(pb, avi->riff_end - url_ftell(pb));
if (get_riff(avi, pb) < 0)
return -1;
tag = get_le32(pb);
size = get_le32(pb);
tag2 = get_le32(pb);
if (tag == MKTAG('L','I','S','T') && tag2 == MKTAG('m','o','v','i'))
avi->movi_end = url_ftell(pb) + size - 4;
else
return -1;
}
for(j=0; j<7; j++)
d[j]= d[j+1];
d[7]= get_byte(pb);
size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
//parse ix##
n= (d[2] - '0') * 10 + (d[3] - '0');
if( d[2] >= '0' && d[2] <= '9'
&& d[3] >= '0' && d[3] <= '9'
&& d[0] == 'i' && d[1] == 'x'
&& n < s->nb_streams
&& i + size <= avi->movi_end){
url_fskip(pb, size);
}
//parse ##dc/##wb
n= (d[0] - '0') * 10 + (d[1] - '0');
if( d[0] >= '0' && d[0] <= '9'
&& d[1] >= '0' && d[1] <= '9'
&& ((d[2] == 'd' && d[3] == 'c') ||
(d[2] == 'w' && d[3] == 'b') ||
(d[2] == 'd' && d[3] == 'b') ||
(d[2] == '_' && d[3] == '_'))
&& n < s->nb_streams
&& i + size <= avi->movi_end) {
av_new_packet(pkt, size);
get_buffer(pb, pkt->data, size);
if (size & 1) {
get_byte(pb);
size++;
}
if (avi->dv_demux) {
dstr = pkt->destruct;
size = dv_produce_packet(avi->dv_demux, pkt,
pkt->data, pkt->size);
pkt->destruct = dstr;
} else {
pkt->stream_index = n;
pkt->flags |= PKT_FLAG_KEY; // FIXME: We really should read
// index for that
}
return size;
}
}
return -1;
}
static int avi_read_close(AVFormatContext *s)
{
int i;
AVIContext *avi = s->priv_data;
for(i=0;i<s->nb_streams;i++) {
AVStream *st = s->streams[i];
// av_free(st->priv_data);
av_free(st->codec.extradata);
}
if (avi->dv_demux)
av_free(avi->dv_demux);
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;
}