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mjpegdec: apply flipping after decoding, not before 

This is simpler and removes a silly restriction on edges being present.
This commit is contained in:
Anton Khirnov 2013-12-20 10:44:57 +01:00
parent e588615d93
commit d48132b7de
2 changed files with 20 additions and 15 deletions
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32
libavcodec/mjpegdec.c
View File

@ -367,6 +367,12 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
s->avctx->pix_fmt = AV_PIX_FMT_GRAY16;
}
s->pix_desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
if (!s->pix_desc) {
av_log(s->avctx, AV_LOG_ERROR, "Could not get a pixel format descriptor.\n");
return AVERROR_BUG;
}
av_frame_unref(s->picture_ptr);
if (ff_get_buffer(s->avctx, s->picture_ptr, AV_GET_BUFFER_FLAG_REF) < 0) {
av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
@ -824,26 +830,12 @@ static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int Ah,
if (mb_bitmask)
init_get_bits(&mb_bitmask_gb, mb_bitmask, s->mb_width * s->mb_height);
if (s->flipped && s->avctx->flags & CODEC_FLAG_EMU_EDGE) {
av_log(s->avctx, AV_LOG_ERROR,
"Can not flip image with CODEC_FLAG_EMU_EDGE set!\n");
s->flipped = 0;
}
for (i = 0; i < nb_components; i++) {
int c = s->comp_index[i];
data[c] = s->picture_ptr->data[c];
reference_data[c] = reference ? reference->data[c] : NULL;
linesize[c] = s->linesize[c];
s->coefs_finished[c] |= 1;
if (s->flipped) {
// picture should be flipped upside-down for this codec
int offset = (linesize[c] * (s->v_scount[i] *
(8 * s->mb_height - ((s->height / s->v_max) & 7)) - 1));
data[c] += offset;
reference_data[c] += offset;
linesize[c] *= -1;
}
}
for (mb_y = 0; mb_y < s->mb_height; mb_y++) {
@ -1464,6 +1456,7 @@ int ff_mjpeg_find_marker(MJpegDecodeContext *s,
int ff_mjpeg_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
AVFrame *frame = data;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MJpegDecodeContext *s = avctx->priv_data;
@ -1585,8 +1578,17 @@ eoi_parser:
if (s->bottom_field == !s->interlace_polarity)
goto not_the_end;
}
if ((ret = av_frame_ref(data, s->picture_ptr)) < 0)
if ((ret = av_frame_ref(frame, s->picture_ptr)) < 0)
return ret;
if (s->flipped) {
int i;
for (i = 0; frame->data[i]; i++) {
int h = frame->height >> ((i == 1 || i == 2) ?
s->pix_desc->log2_chroma_h : 0);
frame->data[i] += frame->linesize[i] * (h - 1);
frame->linesize[i] *= -1;
}
}
*got_frame = 1;
if (!s->lossless &&

3
libavcodec/mjpegdec.h
View File

@ -30,6 +30,7 @@
#define AVCODEC_MJPEGDEC_H
#include "libavutil/log.h"
#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "get_bits.h"
@ -113,6 +114,8 @@ typedef struct MJpegDecodeContext {
unsigned int ljpeg_buffer_size;
int extern_huff;
const AVPixFmtDescriptor *pix_desc;
} MJpegDecodeContext;
int ff_mjpeg_decode_init(AVCodecContext *avctx);