[FFmpeg-devel] [PATCH] lavc/mjpegdec: fix VA-API MJPEG decoding uninitialized huffman table

mypopy at gmail.com mypopy at gmail.com
Tue Oct 30 07:52:01 EET 2018


On Tue, Oct 30, 2018 at 11:41 AM Eoff, Ullysses A
<ullysses.a.eoff at intel.com> wrote:
>
> > -----Original Message-----
> > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf Of mypopy at gmail.com
> > Sent: Monday, October 29, 2018 8:10 PM
> > To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
> > Cc: Zhao, Jun <jun.zhao at intel.com>; Lin, Decai <decai.lin at intel.com>
> > Subject: Re: [FFmpeg-devel] [PATCH] lavc/mjpegdec: fix VA-API MJPEG decoding uninitialized huffman table
> >
> > On Tue, Oct 30, 2018 at 10:41 AM Li, Zhong <zhong.li at intel.com> wrote:
> > >
> > > > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> > > > Of mypopy at gmail.com
> > > > Sent: Tuesday, October 30, 2018 9:02 AM
> > > > To: FFmpeg development discussions and patches
> > > > <ffmpeg-devel at ffmpeg.org>
> > > > Cc: Zhao, Jun <jun.zhao at intel.com>; Lin, Decai <decai.lin at intel.com>
> > > > Subject: Re: [FFmpeg-devel] [PATCH] lavc/mjpegdec: fix VA-API MJPEG
> > > > decoding uninitialized huffman table
> > > >
> > > > On Mon, Oct 29, 2018 at 6:39 PM Li, Zhong <zhong.li at intel.com> wrote:
> > > > >
> > > > > > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On
> > > > > > Behalf Of Jun Zhao
> > > > > > Sent: Monday, October 29, 2018 6:26 PM
> > > > > > To: ffmpeg-devel at ffmpeg.org
> > > > > > Cc: Zhao, Jun <jun.zhao at intel.com>; Lin, Decai <decai.lin at intel.com>
> > > > > > Subject: [FFmpeg-devel] [PATCH] lavc/mjpegdec: fix VA-API MJPEG
> > > > > > decoding uninitialized huffman table
> > > > > >
> > > > > > From: Jun Zhao <jun.zhao at intel.com>
> > > > > >
> > > > > > Now VA-API HWAccel MJPEG decoding uninitialized huffman table, it's
> > > > > > will lead to the decoding error like"Failed to sync surface 0x5: 23
> > > > > > (internal decoding error)." in iHD open source driver.
> > > > > >
> > > > > > Signed-off-by: dlin2 <decai.lin at intel.com>
> > > > > > Signed-off-by: Jun Zhao <jun.zhao at intel.com>
> > > > > > ---
> > > > > >  libavcodec/mjpegdec.c |   19 +++++++++++++++++++
> > > > > >  1 files changed, 19 insertions(+), 0 deletions(-)
> > > > > >
> > > > > > diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c index
> > > > > > b0cb3ff..89effb6 100644
> > > > > > --- a/libavcodec/mjpegdec.c
> > > > > > +++ b/libavcodec/mjpegdec.c
> > > > > > @@ -75,6 +75,25 @@ static int build_vlc(VLC *vlc, const uint8_t
> > > > > > *bits_table, static int build_basic_mjpeg_vlc(MJpegDecodeContext *s)
> > > > {
> > > > > >      int ret;
> > > > > > +    int i;
> > > > > > +
> > > > > > +    /* initialize default huffman tables */
> > > > > > +    for (i = 0; i < 16; i++)
> > > > > > +        s->raw_huffman_lengths[0][0][i] =
> > > > > > avpriv_mjpeg_bits_dc_luminance[i + 1];
> > > > > > +    for (i = 0; i < 12; i++)
> > > > > > +        s->raw_huffman_values[0][0][i] = avpriv_mjpeg_val_dc[i];
> > > > > > +    for (i = 0; i < 16; i++)
> > > > > > +        s->raw_huffman_lengths[0][1][i] =
> > > > > > avpriv_mjpeg_bits_dc_chrominance[i + 1];
> > > > > > +    for (i = 0; i < 12; i++)
> > > > > > +        s->raw_huffman_values[0][1][i] = avpriv_mjpeg_val_dc[i];
> > > > > > +    for (i = 0; i < 16; i++)
> > > > > > +        s->raw_huffman_lengths[1][0][i] =
> > > > > > avpriv_mjpeg_bits_ac_luminance[i + 1];
> > > > > > +    for (i = 0; i < 162; i++)
> > > > > > +        s->raw_huffman_values[1][0][i] =
> > > > > > avpriv_mjpeg_val_ac_luminance[i];
> > > > > > +    for (i = 0; i < 16; i++)
> > > > > > +        s->raw_huffman_lengths[1][1][i] =
> > > > > > avpriv_mjpeg_bits_ac_chrominance[i + 1];
> > > > > > +    for (i = 0; i < 162; i++)
> > > > > > +        s->raw_huffman_values[1][1][i] =
> > > > > > + avpriv_mjpeg_val_ac_chrominance[i];
> > > > > >
> > > > > >      if ((ret = build_vlc(&s->vlcs[0][0],
> > > > avpriv_mjpeg_bits_dc_luminance,
> > > > > >                           avpriv_mjpeg_val_dc, 12, 0, 0)) < 0)
> > > > > > --
> > > > > > 1.7.1
> > > > >
> > > > > Should this be fixed in iHD driver instead of ffmpeg?
> > > > No, I don't think driver is a good place to initialize the huffman table.
> > >
> > > For the default Huffman table, thus should be initialized by driver itself.
> > > For non-default case, thus should be passed from ffmpeg.
> > > So, what is the case you want to fix? Both (if so, no need to mention iHD driver)?
> > Both, now HWAccel MJPEG always setting the huffman table and
> > can't distinguish the HWaccel JPEG whether default Huffman table.
>
> If your VA-API HWAccel MJPEG decoding case(s) work with i965 driver
> and not iHD then I would assume iHD needs fixing.
>
i965 must be have some issue if MJPEG decoding, when I try to dump the
data to CPU to check the frame

LIBVA_DRIVER_NAME=i965 ./ffmpeg -hwaccel vaapi -vaapi_device
/dev/dri/renderD128 -i
~/Videos/logitech_webcam_1280x720_30fps_2980frames.mjpeg -f null
/dev/null
ffmpeg version N-92305-g1ff4bd59df Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-27ubuntu1~18.04)
  configuration: --enable-libx264 --enable-libx265 --enable-gpl
--enable-libwebp --disable-optimizations --samples=../fate-suite
--enable-openssl --enable-nonfree --enable-libzmq --enable-libkvazaar
--enable-libvpx --enable-libvorbis --enable-libsrt
  libavutil      56. 21.100 / 56. 21.100
  libavcodec     58. 34.100 / 58. 34.100
  libavformat    58. 19.102 / 58. 19.102
  libavdevice    58.  4.106 / 58.  4.106
  libavfilter     7. 38.100 /  7. 38.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
[mjpeg @ 0x55949b69a1c0] Format mjpeg detected only with low score of
25, misdetection possible!
Input #0, mjpeg, from
'/home/barry/Videos/logitech_webcam_1280x720_30fps_2980frames.mjpeg':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj422p(pc, bt470bg/unknown/unknown),
1280x720, 25 tbr, 1200k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> wrapped_avframe (native))
Press [q] to stop, [?] for help
[AVHWFramesContext @ 0x55949b6a5240] Failed to read image from surface
0x4000005: 20 (the requested function is not implemented).
[mjpeg @ 0x55949b69d440] Failed to transfer data to output frame: -5.
Error while processing the decoded data for stream #0:0


More information about the ffmpeg-devel mailing list