On Sun, 29 Nov 2020, Nuo Mi wrote:
On Sun, Nov 29, 2020 at 1:54 AM Marton Balint <c...@passwd.hu> wrote:
On Sat, 28 Nov 2020, Nuo Mi wrote:
> following comandline will crash the ffmpeg
> ffmpeg -threads 17 -thread_type slice -i WPP_A_ericsson_MAIN_2.bit
out.yuv -y
>
> the HEVCContext->sList size is MAX_NB_THREADS(16), any > 16 thread
number will crash the application
> ---
> libavcodec/hevcdec.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
> index 699c13bbcc..e1dae150d5 100644
> --- a/libavcodec/hevcdec.c
> +++ b/libavcodec/hevcdec.c
> @@ -3406,7 +3406,7 @@ static av_cold int hevc_decode_free(AVCodecContext
*avctx)
> av_freep(&s->sh.offset);
> av_freep(&s->sh.size);
>
> - for (i = 1; i < s->threads_number; i++) {
> + for (i = 1; i < FFMIN(s->threads_number, MAX_NB_THREADS); i++) {
This should not be needed, if you check the threads_number is
hevc_decode_init.
Yes, It's needed. After the patch, we have two hevc_decode_free in this
function.
Both need this.
Then I think it is better to reorder the initializations in
hevc_decode_init, so that hevc_decode_free is only called after the number
of threads is determined.
Regards,
Marton
> HEVCLocalContext *lc = s->HEVClcList[i];
> if (lc) {
> av_freep(&s->HEVClcList[i]);
> @@ -3608,6 +3608,11 @@ static av_cold int
hevc_decode_init(AVCodecContext *avctx)
> s->threads_type = FF_THREAD_FRAME;
> else
> s->threads_type = FF_THREAD_SLICE;
> + if (s->threads_type == FF_THREAD_SLICE && s->threads_number >
MAX_NB_THREADS) {
> + av_log(s->avctx, AV_LOG_ERROR, "thread number > %d is not
supported.\n", MAX_NB_THREADS);
> + hevc_decode_free(avctx);
> + return AVERROR(EINVAL);
> + }
Is it possible to warn the user but gracefully continue with reduced
number of threads? Mpeg2 decoder seems to do this.
Sure, thanks for the suggestion.
After the change, the FFMIN(s->threads_number, MAX_NB_THREADS) still needed
by
https://github.com/FFmpeg/FFmpeg/blob/394e8bb385a351091cb1ba0be986f3bbb15039fd/libavcodec/hevcdec.c#L3601
Regards,
Marton
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
