[FFmpeg-devel] [FFmpeg-cvslog] lavu/qsv: make a copy as libmfx alignment requirement for uploading

[Mark Thompson]

On 11/10/18 06:38, Zhong Li wrote:
> ffmpeg | branch: master | Zhong Li <zhong.li at intel.com> | Mon Sep 17 19:16:44 2018 +0800| [681aa7d14f97fd98181ca6d61e11be48fe65692d] | committer: Zhong Li
> 
> lavu/qsv: make a copy as libmfx alignment requirement for uploading
> 
> Libmfx requires 16 bytes aligned input/output for uploading.
> Currently only output is 16 byte aligned and assigning same width/height to
> input with smaller buffer size actually, thus definitely will cause segment fault.
> 
> Can reproduce with any 1080p nv12 rawvideo input:
> ffmpeg -init_hw_device qsv=qsv:hw -hwaccel qsv -filter_hw_device qsv -f rawvideo -pix_fmt nv12 -s:v 1920x1080
> -i 1080p_nv12.yuv -vf 'format=nv12,hwupload=extra_hw_frames=16,hwdownload,format=nv12' -an -y out_nv12.yuv
> 
> It can fix #7418
> 
> Signed-off-by: Zhong Li <zhong.li at intel.com>
> 
>> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=681aa7d14f97fd98181ca6d61e11be48fe65692d
> ---
> 
>  libavutil/hwcontext_qsv.c | 31 +++++++++++++++++++++++++++++--
>  1 file changed, 29 insertions(+), 2 deletions(-)
> 
> diff --git a/libavutil/hwcontext_qsv.c b/libavutil/hwcontext_qsv.c
> index 33e121b416..814ce215ce 100644
> --- a/libavutil/hwcontext_qsv.c
> +++ b/libavutil/hwcontext_qsv.c
> @@ -862,6 +862,10 @@ static int qsv_transfer_data_to(AVHWFramesContext *ctx, AVFrame *dst,
>      mfxSyncPoint sync = NULL;
>      mfxStatus err;
>      int ret = 0;
> +    /* make a copy if the input is not padded as libmfx requires */
> +    AVFrame tmp_frame, *src_frame;
> +    int realigned = 0;
> +
>  
>      while (!s->session_upload_init && !s->session_upload && !ret) {
>  #if HAVE_PTHREADS
> @@ -887,16 +891,36 @@ static int qsv_transfer_data_to(AVHWFramesContext *ctx, AVFrame *dst,
>      if (ret < 0)
>          return ret;
>  
> +
> +    if (src->height & 16 || src->linesize[0] & 16) {

Doesn't this still need to check that the layout is compatible with other the limitations that libmfx has before trying to do the upload?  In particular, that the pitches for the different planes are actually all the same - I certainly wouldn't expect them to be for YUV420P.

(IIRC there was a requirement 0 < frame->data[N] - frame->data[0] < 2^24 as well (or something like that, I might be wrong), which also need not be true.)

- Mark