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FFmpeg/libavcodec/mjpegbdec.c
Michael Niedermayer ee77140afa Merge commit 'b2bed9325dbd6be0da1d91ffed3f513c40274fd2'
* commit 'b2bed9325dbd6be0da1d91ffed3f513c40274fd2':
  cosmetics: Group .name and .long_name together in codec/format declarations

Conflicts:
	libavcodec/8svx.c
	libavcodec/alac.c
	libavcodec/cljr.c
	libavcodec/dnxhddec.c
	libavcodec/dnxhdenc.c
	libavcodec/dpxenc.c
	libavcodec/dvdec.c
	libavcodec/dvdsubdec.c
	libavcodec/dvdsubenc.c
	libavcodec/ffv1dec.c
	libavcodec/flacdec.c
	libavcodec/flvdec.c
	libavcodec/fraps.c
	libavcodec/frwu.c
	libavcodec/g726.c
	libavcodec/gif.c
	libavcodec/gifdec.c
	libavcodec/h261dec.c
	libavcodec/h263dec.c
	libavcodec/iff.c
	libavcodec/imc.c
	libavcodec/libopencore-amr.c
	libavcodec/libopenjpegdec.c
	libavcodec/libopenjpegenc.c
	libavcodec/libspeexenc.c
	libavcodec/libvo-amrwbenc.c
	libavcodec/libvorbisenc.c
	libavcodec/libvpxenc.c
	libavcodec/libx264.c
	libavcodec/libxavs.c
	libavcodec/libxvid.c
	libavcodec/ljpegenc.c
	libavcodec/mjpegbdec.c
	libavcodec/mjpegdec.c
	libavcodec/mpeg12dec.c
	libavcodec/mpeg4videodec.c
	libavcodec/msmpeg4dec.c
	libavcodec/pgssubdec.c
	libavcodec/pngdec.c
	libavcodec/pngenc.c
	libavcodec/proresdec_lgpl.c
	libavcodec/proresenc_kostya.c
	libavcodec/ra144enc.c
	libavcodec/rawdec.c
	libavcodec/rv10.c
	libavcodec/sp5xdec.c
	libavcodec/takdec.c
	libavcodec/tta.c
	libavcodec/v210dec.c
	libavcodec/vp6.c
	libavcodec/wavpack.c
	libavcodec/xbmenc.c
	libavcodec/yop.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2013-10-04 12:34:23 +02:00

168 lines
5.5 KiB
C

/*
* Apple MJPEG-B decoder
* Copyright (c) 2002 Alex Beregszaszi
*
* 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
*/
/**
* @file
* Apple MJPEG-B decoder.
*/
#include "avcodec.h"
#include "mjpeg.h"
#include "mjpegdec.h"
static uint32_t read_offs(AVCodecContext *avctx, GetBitContext *gb, uint32_t size, const char *err_msg){
uint32_t offs= get_bits_long(gb, 32);
if(offs >= size){
av_log(avctx, AV_LOG_WARNING, err_msg, offs, size);
return 0;
}
return offs;
}
static int mjpegb_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MJpegDecodeContext *s = avctx->priv_data;
const uint8_t *buf_end, *buf_ptr;
GetBitContext hgb; /* for the header */
uint32_t dqt_offs, dht_offs, sof_offs, sos_offs, second_field_offs;
uint32_t field_size, sod_offs;
int ret;
buf_ptr = buf;
buf_end = buf + buf_size;
s->got_picture = 0;
read_header:
/* reset on every SOI */
s->restart_interval = 0;
s->restart_count = 0;
s->mjpb_skiptosod = 0;
if (buf_end - buf_ptr >= 1 << 28)
return AVERROR_INVALIDDATA;
init_get_bits(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr)*8);
skip_bits(&hgb, 32); /* reserved zeros */
if (get_bits_long(&hgb, 32) != MKBETAG('m','j','p','g'))
{
av_log(avctx, AV_LOG_WARNING, "not mjpeg-b (bad fourcc)\n");
return AVERROR_INVALIDDATA;
}
field_size = get_bits_long(&hgb, 32); /* field size */
av_log(avctx, AV_LOG_DEBUG, "field size: 0x%x\n", field_size);
skip_bits(&hgb, 32); /* padded field size */
second_field_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "second_field_offs is %d and size is %d\n");
av_log(avctx, AV_LOG_DEBUG, "second field offs: 0x%x\n", second_field_offs);
dqt_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "dqt is %d and size is %d\n");
av_log(avctx, AV_LOG_DEBUG, "dqt offs: 0x%x\n", dqt_offs);
if (dqt_offs)
{
init_get_bits(&s->gb, buf_ptr+dqt_offs, (buf_end - (buf_ptr+dqt_offs))*8);
s->start_code = DQT;
if (ff_mjpeg_decode_dqt(s) < 0 &&
(avctx->err_recognition & AV_EF_EXPLODE))
return AVERROR_INVALIDDATA;
}
dht_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "dht is %d and size is %d\n");
av_log(avctx, AV_LOG_DEBUG, "dht offs: 0x%x\n", dht_offs);
if (dht_offs)
{
init_get_bits(&s->gb, buf_ptr+dht_offs, (buf_end - (buf_ptr+dht_offs))*8);
s->start_code = DHT;
ff_mjpeg_decode_dht(s);
}
sof_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sof is %d and size is %d\n");
av_log(avctx, AV_LOG_DEBUG, "sof offs: 0x%x\n", sof_offs);
if (sof_offs)
{
init_get_bits(&s->gb, buf_ptr+sof_offs, (buf_end - (buf_ptr+sof_offs))*8);
s->start_code = SOF0;
if (ff_mjpeg_decode_sof(s) < 0)
return -1;
}
sos_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sos is %d and size is %d\n");
av_log(avctx, AV_LOG_DEBUG, "sos offs: 0x%x\n", sos_offs);
sod_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sof is %d and size is %d\n");
av_log(avctx, AV_LOG_DEBUG, "sod offs: 0x%x\n", sod_offs);
if (sos_offs)
{
init_get_bits(&s->gb, buf_ptr + sos_offs,
8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs));
s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
s->start_code = SOS;
if (ff_mjpeg_decode_sos(s, NULL, NULL) < 0 &&
(avctx->err_recognition & AV_EF_EXPLODE))
return AVERROR_INVALIDDATA;
}
if (s->interlaced) {
s->bottom_field ^= 1;
/* if not bottom field, do not output image yet */
if (s->bottom_field != s->interlace_polarity && second_field_offs)
{
buf_ptr = buf + second_field_offs;
goto read_header;
}
}
//XXX FIXME factorize, this looks very similar to the EOI code
if(!s->got_picture) {
av_log(avctx, AV_LOG_WARNING, "no picture\n");
return buf_size;
}
if ((ret = av_frame_ref(data, s->picture_ptr)) < 0)
return ret;
*got_frame = 1;
if (!s->lossless && avctx->debug & FF_DEBUG_QP) {
av_log(avctx, AV_LOG_DEBUG, "QP: %d\n",
FFMAX3(s->qscale[0], s->qscale[1], s->qscale[2]));
}
return buf_size;
}
AVCodec ff_mjpegb_decoder = {
.name = "mjpegb",
.long_name = NULL_IF_CONFIG_SMALL("Apple MJPEG-B"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MJPEGB,
.priv_data_size = sizeof(MJpegDecodeContext),
.init = ff_mjpeg_decode_init,
.close = ff_mjpeg_decode_end,
.decode = mjpegb_decode_frame,
.capabilities = CODEC_CAP_DR1,
.max_lowres = 3,
};