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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"
#undef NDEBUG
#include <assert.h>
//#define DEBUG
//#define DEBUG_SEEK
typedef struct AVIStream {
int64_t frame_offset; /* current frame (video) or byte (audio) counter
(used to compute the pts) */
int remaining;
int packet_size;
int scale;
int rate;
int sample_size; /* audio only data */
int start;
int cum_len; /* temporary storage (used during seek) */
int prefix; ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'
int prefix_count;
} AVIStream;
typedef struct {
int64_t riff_end;
int64_t movi_end;
offset_t movi_list;
int index_loaded;
int is_odml;
int non_interleaved;
int stream_index;
DVDemuxContext* dv_demux;
} AVIContext;
static int avi_load_index(AVFormatContext *s);
#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;
unsigned int size, nb_frames;
int i, n;
AVStream *st;
AVIStream *ast;
int xan_video = 0; /* hack to support Xan A/V */
avi->stream_index= -1;
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_list = url_ftell(pb) - 4;
if(size) avi->movi_end = avi->movi_list + size;
else avi->movi_end = url_fsize(pb);
#ifdef DEBUG
printf("movi end=%Lx\n", avi->movi_end);
#endif
goto end_of_header;
}
break;
case MKTAG('d', 'm', 'l', 'h'):
avi->is_odml = 1;
url_fskip(pb, size + (size & 1));
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++) {
AVIStream *ast;
st = av_new_stream(s, i);
if (!st)
goto fail;
ast = av_mallocz(sizeof(AVIStream));
if (!ast)
goto fail;
st->priv_data = ast;
}
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 */
#ifdef DEBUG
print_tag("strh", tag1, -1);
#endif
if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == 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;
ast = s->streams[0]->priv_data;
av_freep(&s->streams[0]->codec.extradata);
av_freep(&s->streams[0]);
s->nb_streams = 0;
avi->dv_demux = dv_init_demux(s);
if (!avi->dv_demux)
goto fail;
s->streams[0]->priv_data = ast;
url_fskip(pb, 3 * 4);
ast->scale = get_le32(pb);
ast->rate = get_le32(pb);
stream_index = s->nb_streams - 1;
url_fskip(pb, size - 7*4);
break;
}
if (stream_index >= s->nb_streams) {
url_fskip(pb, size - 8);
break;
}
st = s->streams[stream_index];
ast = st->priv_data;
st->codec.stream_codec_tag= handler;
get_le32(pb); /* flags */
get_le16(pb); /* priority */
get_le16(pb); /* language */
get_le32(pb); /* initial frame */
ast->scale = get_le32(pb);
ast->rate = get_le32(pb);
if(ast->scale && ast->rate){
}else if(frame_period){
ast->rate = 1000000;
ast->scale = frame_period;
}else{
ast->rate = 25;
ast->scale = 1;
}
av_set_pts_info(st, 64, ast->scale, ast->rate);
ast->start= get_le32(pb); /* start */
nb_frames = get_le32(pb);
st->start_time = 0;
st->duration = nb_frames;
get_le32(pb); /* buffer size */
get_le32(pb); /* quality */
ast->sample_size = get_le32(pb); /* sample ssize */
// av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
switch(tag1) {
case MKTAG('v', 'i', 'd', 's'):
codec_type = CODEC_TYPE_VIDEO;
ast->sample_size = 0;
break;
case MKTAG('a', 'u', 'd', 's'):
codec_type = CODEC_TYPE_AUDIO;
break;
case MKTAG('t', 'x', 't', 's'):
//FIXME
codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ? FIXME
break;
case MKTAG('p', 'a', 'd', 's'):
codec_type = CODEC_TYPE_UNKNOWN;
stream_index--;
break;
default:
av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
goto fail;
}
url_fskip(pb, size - 12 * 4);
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 */
if(size > 10*4 && size<(1<<30)){
st->codec.extradata_size= size - 10*4;
st->codec.extradata= av_malloc(st->codec.extradata_size + FF_INPUT_BUFFER_PADDING_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);
/* Extract palette from extradata if bpp <= 8 */
/* This code assumes that extradata contains only palette */
/* This is true for all paletted codecs implemented in ffmpeg */
if (st->codec.extradata_size && (st->codec.bits_per_sample <= 8)) {
st->codec.palctrl = av_mallocz(sizeof(AVPaletteControl));
#ifdef WORDS_BIGENDIAN
for (i = 0; i < FFMIN(st->codec.extradata_size, AVPALETTE_SIZE)/4; i++)
st->codec.palctrl->palette[i] = bswap_32(((uint32_t*)st->codec.extradata)[i]);
#else
memcpy(st->codec.palctrl->palette, st->codec.extradata,
FFMIN(st->codec.extradata_size, AVPALETTE_SIZE));
#endif
st->codec.palctrl->palette_changed = 1;
}
#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 */
st->need_parsing = 1;
/* force parsing as several audio frames can be in
one packet */
if (xan_video)
st->codec.codec_id = CODEC_ID_XAN_DPCM;
break;
default:
st->codec.codec_type = CODEC_TYPE_DATA;
st->codec.codec_id= CODEC_ID_NONE;
st->codec.codec_tag= 0;
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;
}
assert(!avi->index_loaded);
avi_load_index(s);
avi->index_loaded = 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;
offset_t i, sync;
void* dstr;
if (avi->dv_demux) {
size = dv_get_packet(avi->dv_demux, pkt);
if (size >= 0)
return size;
}
if(avi->non_interleaved){
int best_stream_index;
AVStream *best_st= NULL;
AVIStream *best_ast;
int64_t best_ts= INT64_MAX;
int i;
for(i=0; i<s->nb_streams; i++){
AVStream *st = s->streams[i];
AVIStream *ast = st->priv_data;
int64_t ts= ast->frame_offset;
if(ast->sample_size)
ts /= ast->sample_size;
ts= av_rescale(ts, AV_TIME_BASE * (int64_t)st->time_base.num, st->time_base.den);
// av_log(NULL, AV_LOG_DEBUG, "%Ld %d/%d %Ld\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
if(ts < best_ts){
best_ts= ts;
best_st= st;
best_stream_index= i;
}
}
best_ast = best_st->priv_data;
best_ts= av_rescale(best_ts, best_st->time_base.den, AV_TIME_BASE * (int64_t)best_st->time_base.num); //FIXME a little ugly
if(best_ast->remaining)
i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
else
i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
// av_log(NULL, AV_LOG_DEBUG, "%d\n", i);
if(i>=0){
int64_t pos= best_st->index_entries[i].pos;
pos += avi->movi_list + best_ast->packet_size - best_ast->remaining;
url_fseek(&s->pb, pos, SEEK_SET);
// av_log(NULL, AV_LOG_DEBUG, "pos=%Ld\n", pos);
if(best_ast->remaining)
avi->stream_index= best_stream_index;
else
avi->stream_index= -1;
}
}
resync:
if(avi->stream_index >= 0){
AVStream *st= s->streams[ avi->stream_index ];
AVIStream *ast= st->priv_data;
int size;
if(ast->sample_size == 0)
size= INT_MAX;
else if(ast->sample_size < 32)
size= 64*ast->sample_size;
else
size= ast->sample_size;
if(size > ast->remaining)
size= ast->remaining;
av_new_packet(pkt, size);
get_buffer(pb, pkt->data, size);
if (avi->dv_demux) {
dstr = pkt->destruct;
size = dv_produce_packet(avi->dv_demux, pkt,
pkt->data, pkt->size);
pkt->destruct = dstr;
pkt->flags |= PKT_FLAG_KEY;
} else {
/* XXX: how to handle B frames in avi ? */
pkt->dts = ast->frame_offset;
// pkt->dts += ast->start;
if(ast->sample_size)
pkt->dts /= ast->sample_size;
//av_log(NULL, AV_LOG_DEBUG, "dts:%Ld offset:%d %d/%d smpl_siz:%d base:%d st:%d size:%d\n", pkt->dts, ast->frame_offset, ast->scale, ast->rate, ast->sample_size, AV_TIME_BASE, n, size);
pkt->stream_index = avi->stream_index;
if (st->codec.codec_type == CODEC_TYPE_VIDEO) {
if(st->index_entries){
AVIndexEntry *e;
int index;
index= av_index_search_timestamp(st, pkt->dts, 0);
e= &st->index_entries[index];
if(index >= 0 && e->timestamp == ast->frame_offset){
if (e->flags & AVINDEX_KEYFRAME)
pkt->flags |= PKT_FLAG_KEY;
}
} else {
/* if no index, better to say that all frames
are key frames */
pkt->flags |= PKT_FLAG_KEY;
}
} else {
pkt->flags |= PKT_FLAG_KEY;
}
if(ast->sample_size)
ast->frame_offset += pkt->size;
else
ast->frame_offset++;
}
ast->remaining -= size;
if(!ast->remaining){
avi->stream_index= -1;
ast->packet_size= 0;
if (size & 1) {
get_byte(pb);
size++;
}
}
return size;
}
memset(d, -1, sizeof(int)*8);
for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
int j;
if (i >= avi->movi_end) {
if (avi->is_odml) {
url_fskip(pb, avi->riff_end - i);
avi->riff_end = avi->movi_end = url_fsize(pb);
} else
break;
}
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);
if( d[2] >= '0' && d[2] <= '9'
&& d[3] >= '0' && d[3] <= '9'){
n= (d[2] - '0') * 10 + (d[3] - '0');
}else{
n= 100; //invalid stream id
}
//av_log(NULL, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %lld %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
if(i + size > avi->movi_end || d[0]<0)
continue;
//parse ix##
if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
//parse JUNK
||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')){
url_fskip(pb, size);
//av_log(NULL, AV_LOG_DEBUG, "SKIP\n");
goto resync;
}
if( d[0] >= '0' && d[0] <= '9'
&& d[1] >= '0' && d[1] <= '9'){
n= (d[0] - '0') * 10 + (d[1] - '0');
}else{
n= 100; //invalid stream id
}
//parse ##dc/##wb
if(n < s->nb_streams){
AVStream *st;
AVIStream *ast;
st = s->streams[n];
ast = st->priv_data;
if( (st->discard >= AVDISCARD_DEFAULT && size==0)
/*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & PKT_FLAG_KEY))*/ //FIXME needs a little reordering
|| st->discard >= AVDISCARD_ALL){
if(ast->sample_size) ast->frame_offset += pkt->size;
else ast->frame_offset++;
url_fskip(pb, size);
goto resync;
}
if( ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
d[2]*256+d[3] == ast->prefix /*||
(d[2] == 'd' && d[3] == 'c') ||
(d[2] == 'w' && d[3] == 'b')*/) {
//av_log(NULL, AV_LOG_DEBUG, "OK\n");
if(d[2]*256+d[3] == ast->prefix)
ast->prefix_count++;
else{
ast->prefix= d[2]*256+d[3];
ast->prefix_count= 0;
}
avi->stream_index= n;
ast->packet_size= size + 8;
ast->remaining= size;
goto resync;
}
}
/* palette changed chunk */
if ( d[0] >= '0' && d[0] <= '9'
&& d[1] >= '0' && d[1] <= '9'
&& ((d[2] == 'p' && d[3] == 'c'))
&& n < s->nb_streams && i + size <= avi->movi_end) {
AVStream *st;
int first, clr, flags, k, p;
st = s->streams[n];
first = get_byte(pb);
clr = get_byte(pb);
if(!clr) /* all 256 colors used */
clr = 256;
flags = get_le16(pb);
p = 4;
for (k = first; k < clr + first; k++) {
int r, g, b;
r = get_byte(pb);
g = get_byte(pb);
b = get_byte(pb);
get_byte(pb);
st->codec.palctrl->palette[k] = b + (g << 8) + (r << 16);
}
st->codec.palctrl->palette_changed = 1;
goto resync;
}
}
return -1;
}
/* XXX: we make the implicit supposition that the position are sorted
for each stream */
static int avi_read_idx1(AVFormatContext *s, int size)
{
AVIContext *avi = s->priv_data;
ByteIOContext *pb = &s->pb;
int nb_index_entries, i;
AVStream *st;
AVIStream *ast;
unsigned int index, tag, flags, pos, len;
unsigned last_pos= -1;
nb_index_entries = size / 16;
if (nb_index_entries <= 0)
return -1;
/* read the entries and sort them in each stream component */
for(i = 0; i < nb_index_entries; i++) {
tag = get_le32(pb);
flags = get_le32(pb);
pos = get_le32(pb);
len = get_le32(pb);
#if defined(DEBUG_SEEK)
av_log(NULL, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
i, tag, flags, pos, len);
#endif
if(i==0 && pos > avi->movi_list)
avi->movi_list= 0; //FIXME better check
index = ((tag & 0xff) - '0') * 10;
index += ((tag >> 8) & 0xff) - '0';
if (index >= s->nb_streams)
continue;
st = s->streams[index];
ast = st->priv_data;
#if defined(DEBUG_SEEK)
av_log(NULL, AV_LOG_DEBUG, "%d cum_len=%d\n", len, ast->cum_len);
#endif
if(last_pos == pos)
avi->non_interleaved= 1;
else
av_add_index_entry(st, pos, ast->cum_len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
if(ast->sample_size)
ast->cum_len += len / ast->sample_size;
else
ast->cum_len ++;
last_pos= pos;
}
return 0;
}
static int guess_ni_flag(AVFormatContext *s){
AVIContext *avi = s->priv_data;
int i;
int64_t last_start=0;
int64_t first_end= INT64_MAX;
for(i=0; i<s->nb_streams; i++){
AVStream *st = s->streams[i];
AVIStream *ast = st->priv_data;
int n= st->nb_index_entries;
if(n <= 0)
continue;
if(st->index_entries[0].pos > last_start)
last_start= st->index_entries[0].pos;
if(st->index_entries[n-1].pos < first_end)
first_end= st->index_entries[n-1].pos;
}
return last_start > first_end;
}
static int avi_load_index(AVFormatContext *s)
{
AVIContext *avi = s->priv_data;
ByteIOContext *pb = &s->pb;
uint32_t tag, size;
offset_t pos= url_ftell(pb);
url_fseek(pb, avi->movi_end, SEEK_SET);
#ifdef DEBUG_SEEK
printf("movi_end=0x%llx\n", avi->movi_end);
#endif
for(;;) {
if (url_feof(pb))
break;
tag = get_le32(pb);
size = get_le32(pb);
#ifdef DEBUG_SEEK
printf("tag=%c%c%c%c size=0x%x\n",
tag & 0xff,
(tag >> 8) & 0xff,
(tag >> 16) & 0xff,
(tag >> 24) & 0xff,
size);
#endif
switch(tag) {
case MKTAG('i', 'd', 'x', '1'):
if (avi_read_idx1(s, size) < 0)
goto skip;
else
goto the_end;
break;
default:
skip:
size += (size & 1);
url_fskip(pb, size);
break;
}
}
the_end:
avi->non_interleaved |= guess_ni_flag(s);
url_fseek(pb, pos, SEEK_SET);
return 0;
}
static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
AVIContext *avi = s->priv_data;
AVStream *st;
int i, index;
int64_t pos;
if (!avi->index_loaded) {
/* we only load the index on demand */
avi_load_index(s);
avi->index_loaded = 1;
}
assert(stream_index>= 0);
st = s->streams[stream_index];
index= av_index_search_timestamp(st, timestamp, flags);
if(index<0)
return -1;
/* find the position */
pos = st->index_entries[index].pos;
timestamp = st->index_entries[index].timestamp;
// av_log(NULL, AV_LOG_DEBUG, "XX %Ld %d %Ld\n", timestamp, index, st->index_entries[index].timestamp);
for(i = 0; i < s->nb_streams; i++) {
AVStream *st2 = s->streams[i];
AVIStream *ast2 = st2->priv_data;
ast2->packet_size=
ast2->remaining= 0;
if (st2->nb_index_entries <= 0)
continue;
// assert(st2->codec.block_align);
assert(st2->time_base.den == ast2->rate);
assert(st2->time_base.num == ast2->scale);
index = av_index_search_timestamp(
st2,
av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
flags | AVSEEK_FLAG_BACKWARD);
if(index<0)
index=0;
if(!avi->non_interleaved){
while(index>0 && st2->index_entries[index].pos > pos)
index--;
while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
index++;
}
// av_log(NULL, AV_LOG_DEBUG, "%Ld %d %Ld\n", timestamp, index, st2->index_entries[index].timestamp);
/* extract the current frame number */
ast2->frame_offset = st2->index_entries[index].timestamp;
if(ast2->sample_size)
ast2->frame_offset *=ast2->sample_size;
}
if (avi->dv_demux)
dv_flush_audio_packets(avi->dv_demux);
/* do the seek */
pos += avi->movi_list;
url_fseek(&s->pb, pos, SEEK_SET);
avi->stream_index= -1;
return 0;
}
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];
AVIStream *ast = st->priv_data;
av_free(ast);
av_free(st->codec.extradata);
av_free(st->codec.palctrl);
}
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,
avi_read_seek,
};
int avidec_init(void)
{
av_register_input_format(&avi_iformat);
return 0;
}