smvjpegdec: only extract picture when a picture has been decoded.

Fixes null pointer dereference

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-06-07 14:20:59 +02:00
parent 369684f109
commit bce2ed5559

View File

@ -36,6 +36,7 @@ typedef struct SMVJpegDecodeContext {
AVFrame *picture[2]; /* pictures array */
AVCodecContext* avctx;
int frames_per_jpeg;
int mjpeg_data_size;
} SMVJpegDecodeContext;
static inline void smv_img_pnt_plane(uint8_t **dst, uint8_t *src,
@ -131,9 +132,10 @@ static int smvjpeg_decode_frame(AVCodecContext *avctx, void *data, int *data_siz
/* Are we at the start of a block? */
if (!cur_frame)
ret = avcodec_decode_video2(s->avctx, mjpeg_data, data_size, avpkt);
else /*use the last lot... */
*data_size = sizeof(AVPicture);
ret = avcodec_decode_video2(s->avctx, mjpeg_data, &s->mjpeg_data_size, avpkt);
/*use the last lot... */
*data_size = s->mjpeg_data_size;
avctx->pix_fmt = s->avctx->pix_fmt;
@ -142,6 +144,7 @@ static int smvjpeg_decode_frame(AVCodecContext *avctx, void *data, int *data_siz
avcodec_set_dimensions(avctx, mjpeg_data->width,
mjpeg_data->height / s->frames_per_jpeg);
if (*data_size) {
s->picture[1]->extended_data = NULL;
s->picture[1]->width = avctx->width;
s->picture[1]->height = avctx->height;
@ -153,6 +156,7 @@ static int smvjpeg_decode_frame(AVCodecContext *avctx, void *data, int *data_siz
s->picture[1]->linesize[i] = mjpeg_data->linesize[i];
ret = av_frame_ref(data, s->picture[1]);
}
return ret;
}