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ffmpeg/libavformat/dxa.c

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/*
* DXA demuxer
* Copyright (c) 2007 Konstantin Shishkov
*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <inttypes.h>
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
#include "riff.h"
#define DXA_EXTRA_SIZE 9
typedef struct DXAContext {
int frames;
int has_sound;
int bpc;
uint32_t bytes_left;
int64_t wavpos, vidpos;
int readvid;
}DXAContext;
static int dxa_probe(const AVProbeData *p)
{
int w, h;
if (p->buf_size < 15)
return 0;
w = AV_RB16(p->buf + 11);
h = AV_RB16(p->buf + 13);
/* check file header */
if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
p->buf[2] == 'X' && p->buf[3] == 'A' &&
w && w <= 2048 && h && h <= 2048)
return AVPROBE_SCORE_MAX;
else
return 0;
}
static int dxa_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
DXAContext *c = s->priv_data;
AVStream *st, *ast;
uint32_t tag;
int32_t fps;
int w, h;
int num, den;
int flags;
int ret;
tag = avio_rl32(pb);
if (tag != MKTAG('D', 'E', 'X', 'A'))
return AVERROR_INVALIDDATA;
flags = avio_r8(pb);
c->frames = avio_rb16(pb);
if(!c->frames){
av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
return AVERROR_INVALIDDATA;
}
fps = avio_rb32(pb);
if(fps > 0){
den = 1000;
num = fps;
}else if (fps < 0 && fps > INT_MIN){
den = 100000;
num = -fps;
}else{
den = 10;
num = 1;
}
w = avio_rb16(pb);
h = avio_rb16(pb);
c->has_sound = 0;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
// Parse WAV data header
if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){
uint32_t size, fsize;
c->has_sound = 1;
size = avio_rb32(pb);
c->vidpos = avio_tell(pb) + size;
avio_skip(pb, 16);
fsize = avio_rl32(pb);
ast = avformat_new_stream(s, NULL);
if (!ast)
return AVERROR(ENOMEM);
ret = ff_get_wav_header(s, pb, ast->codecpar, fsize, 0);
if (ret < 0)
return ret;
if (ast->codecpar->sample_rate > 0)
avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);
// find 'data' chunk
while(avio_tell(pb) < c->vidpos && !avio_feof(pb)){
tag = avio_rl32(pb);
fsize = avio_rl32(pb);
if(tag == MKTAG('d', 'a', 't', 'a')) break;
avio_skip(pb, fsize);
}
c->bpc = (fsize + (int64_t)c->frames - 1) / c->frames;
if(ast->codecpar->block_align) {
if (c->bpc > INT_MAX - ast->codecpar->block_align + 1)
return AVERROR_INVALIDDATA;
c->bpc = ((c->bpc + ast->codecpar->block_align - 1) / ast->codecpar->block_align) * ast->codecpar->block_align;
}
c->bytes_left = fsize;
c->wavpos = avio_tell(pb);
avio_seek(pb, c->vidpos, SEEK_SET);
}
/* now we are ready: build format streams */
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_DXA;
st->codecpar->width = w;
st->codecpar->height = h;
av_reduce(&den, &num, den, num, (1UL<<31)-1);
avpriv_set_pts_info(st, 33, num, den);
/* flags & 0x80 means that image is interlaced,
* flags & 0x40 means that image has double height
* either way set true height
*/
if(flags & 0xC0){
st->codecpar->height >>= 1;
}
c->readvid = !c->has_sound;
c->vidpos = avio_tell(pb);
s->start_time = 0;
s->duration = av_rescale(c->frames, AV_TIME_BASE * (int64_t)num, den);
av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
return 0;
}
static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
{
DXAContext *c = s->priv_data;
int ret;
uint32_t size;
uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
int pal_size = 0;
if(!c->readvid && c->has_sound && c->bytes_left){
c->readvid = 1;
avio_seek(s->pb, c->wavpos, SEEK_SET);
size = FFMIN(c->bytes_left, c->bpc);
ret = av_get_packet(s->pb, pkt, size);
pkt->stream_index = 1;
if(ret != size)
return AVERROR(EIO);
c->bytes_left -= size;
c->wavpos = avio_tell(s->pb);
return 0;
}
avio_seek(s->pb, c->vidpos, SEEK_SET);
while(!avio_feof(s->pb) && c->frames){
uint32_t tag;
if ((ret = avio_read(s->pb, buf, 4)) != 4) {
av_log(s, AV_LOG_ERROR, "failed reading chunk type\n");
return ret < 0 ? ret : AVERROR_INVALIDDATA;
}
tag = AV_RL32(buf);
switch (tag) {
case MKTAG('N', 'U', 'L', 'L'):
if ((ret = av_new_packet(pkt, 4 + pal_size)) < 0)
return ret;
pkt->stream_index = 0;
if(pal_size) memcpy(pkt->data, pal, pal_size);
memcpy(pkt->data + pal_size, buf, 4);
c->frames--;
c->vidpos = avio_tell(s->pb);
c->readvid = 0;
return 0;
case MKTAG('C', 'M', 'A', 'P'):
pal_size = 768+4;
memcpy(pal, buf, 4);
avio_read(s->pb, pal + 4, 768);
break;
case MKTAG('F', 'R', 'A', 'M'):
if ((ret = avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4)) != DXA_EXTRA_SIZE - 4) {
av_log(s, AV_LOG_ERROR, "failed reading dxa_extra\n");
return ret < 0 ? ret : AVERROR_INVALIDDATA;
}
size = AV_RB32(buf + 5);
if(size > 0xFFFFFF){
av_log(s, AV_LOG_ERROR, "Frame size is too big: %"PRIu32"\n",
size);
return AVERROR_INVALIDDATA;
}
ret = av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size);
if (ret < 0)
return ret;
memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
if(ret != size){
return AVERROR(EIO);
}
if(pal_size) memcpy(pkt->data, pal, pal_size);
pkt->stream_index = 0;
c->frames--;
c->vidpos = avio_tell(s->pb);
c->readvid = 0;
return 0;
default:
av_log(s, AV_LOG_ERROR, "Unknown tag %s\n", av_fourcc2str(tag));
return AVERROR_INVALIDDATA;
}
}
return AVERROR_EOF;
}
AVInputFormat ff_dxa_demuxer = {
.name = "dxa",
.long_name = NULL_IF_CONFIG_SMALL("DXA"),
.priv_data_size = sizeof(DXAContext),
.read_probe = dxa_probe,
.read_header = dxa_read_header,
.read_packet = dxa_read_packet,
};
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