ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinha...@outlook.com> | Tue Jan 25 23:07:25 2022 +0100| [d4d87f2ac56e13aaad68f2dd2efc69a977e6a3bc] | committer: Andreas Rheinhardt
avcodec/mpegvideo: Fix crash when using lowres with 10bit MPEG-4 In this case the macroblocks written to are smaller, yet the MPEG-4 Simple Studio Profile code for 10bit DPCM ignored this; e.g. in case of lowres = 2 or = 3, the sample mpeg4_sstp_dpcm.m4v from the FATE-suite reads beyond the end of the buffer. This commit fixes this by taking lowres into account. The DPCM macroblocks of the aforementioned sample look as good as can be expected after this patch; yet the non-DPCM coded macroblocks are simply corrupt. Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d4d87f2ac56e13aaad68f2dd2efc69a977e6a3bc --- libavcodec/mpegvideo.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c index 47603c2991..40494fe115 100644 --- a/libavcodec/mpegvideo.c +++ b/libavcodec/mpegvideo.c @@ -1629,13 +1629,17 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t block[12][64], uint16_t *dest_pcm[3] = {(uint16_t*)dest_y, (uint16_t*)dest_cb, (uint16_t*)dest_cr}; int linesize[3] = {dct_linesize, uvlinesize, uvlinesize}; for(i = 0; i < 3; i++) { + const int16_t *src = (*s->dpcm_macroblock)[i]; int idx = 0; int vsub = i ? s->chroma_y_shift : 0; int hsub = i ? s->chroma_x_shift : 0; - for(h = 0; h < (16 >> vsub); h++){ - for(w = 0; w < (16 >> hsub); w++) - dest_pcm[i][w] = (*s->dpcm_macroblock)[i][idx++]; + int lowres = lowres_flag ? s->avctx->lowres : 0; + int step = 1 << lowres; + for (h = 0; h < (16 >> (vsub + lowres)); h++){ + for (w = 0, idx = 0; w < (16 >> (hsub + lowres)); w++, idx += step) + dest_pcm[i][w] = src[idx]; dest_pcm[i] += linesize[i] / 2; + src += (16 >> hsub) * step; } } } else { @@ -1644,13 +1648,17 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t block[12][64], int linesize[3] = {dct_linesize, uvlinesize, uvlinesize}; av_assert2(s->dpcm_direction == -1); for(i = 0; i < 3; i++) { + const int16_t *src = (*s->dpcm_macroblock)[i]; int idx = 0; int vsub = i ? s->chroma_y_shift : 0; int hsub = i ? s->chroma_x_shift : 0; + int lowres = lowres_flag ? s->avctx->lowres : 0; + int step = 1 << lowres; dest_pcm[i] += (linesize[i] / 2) * ((16 >> vsub) - 1); - for (h = (16 >> vsub) - 1; h >= 0; h--) { - for (w = (16 >> hsub) - 1; w >= 0; w--) - dest_pcm[i][w] = (*s->dpcm_macroblock)[i][idx++]; + for (h = (16 >> (vsub + lowres)) - 1; h >= 0; h--){ + for (w = (16 >> (hsub + lowres)) - 1, idx = 0; w >= 0; w--, idx += step) + dest_pcm[i][w] = src[idx]; + src += step * (16 >> hsub); dest_pcm[i] -= linesize[i] / 2; } } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
