[FFmpeg-devel] [PATCH 1/2] avformat/dashenc: Set VP9 codec string with profile, level and bitdepth

[Jeyapal, Karthick]

On 4/18/18 7:12 PM, James Almer wrote:
> On 4/18/2018 9:03 AM, Karthick J wrote:
> > From: Karthick Jeyapal <kjeyapal at akamai.com>
> > 
> > Otherwise some versions of chrome browser returns "codec not supported" error
> > ---
> >  libavformat/dashenc.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++-
> >  1 file changed, 78 insertions(+), 1 deletion(-)
> > 
> > diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> > index 9e72636..5443e31 100644
> > --- a/libavformat/dashenc.c
> > +++ b/libavformat/dashenc.c
> > @@ -170,6 +170,79 @@ static void dashenc_io_close(AVFormatContext *s, AVIOContext **pb, char *filenam
> >      }
> >  }
> >  
> > +static void set_vp9_codec_str(AVCodecParameters *par, char *str, int size) {
> > +    int profile, level, bitdepth;
> > +    int picture_size = par->width * par->height;
> > +    switch (par->format) {
> > +    case AV_PIX_FMT_YUV420P:
> > +    case AV_PIX_FMT_YUVA420P:
> > +        bitdepth = 8;
> > +        profile = 0;
> > +        break;
> > +    case AV_PIX_FMT_YUV422P:
> > +    case AV_PIX_FMT_YUV440P:
> > +    case AV_PIX_FMT_GBRP:
> > +    case AV_PIX_FMT_YUV444P:
> > +        bitdepth = 8;
> > +        profile = 1;
> > +        break;
> > +    case AV_PIX_FMT_YUV420P10:
> > +        bitdepth = 10;
> > +        profile = 2;
> > +        break;
> > +    case AV_PIX_FMT_YUV420P12:
> > +        bitdepth = 12;
> > +        profile = 2;
> > +        break;
> > +    case AV_PIX_FMT_YUV422P10:
> > +    case AV_PIX_FMT_YUV440P10:
> > +    case AV_PIX_FMT_GBRP10:
> > +    case AV_PIX_FMT_YUV444P10:
> > +        bitdepth = 10;
> > +        profile = 3;
> > +        break;
> > +    case AV_PIX_FMT_YUV422P12:
> > +    case AV_PIX_FMT_YUV440P12:
> > +    case AV_PIX_FMT_GBRP12:
> > +    case AV_PIX_FMT_YUV444P12:
> > +        bitdepth = 12;
> > +        profile = 3;
> > +        break;
> > +    default:
> > +        goto error;
> > +    }
>
> This is too big and unwieldy, you're not looking at par->profile first
> (which is more than likely set to the correct value already), also
> you're in any case not using the FF_PROFILE constants either.
>
> And you should reuse as much code from vpcc.c as possible here. It will
> be needed in other muxers like Matroska soon enough either way.
> I'll send a patch in a moment to make that file usable for cases like
> this one.
>
> > +    // Finding VP9 level accurately in a ffmpeg muxer is almost impossible.
> > +    // Hence we will set approximate levels based on the width and height.
>
> You should check for par->level first, to see if it's not
> FF_LEVEL_UNKNOWN (chances are it is, though).
> Also, this should be implemented to vpcc.c, so it can be reused there to
> write the vpcc atom for mp4 output (it's currently writing 0 when level
> is unknown, which is probably wrong).
Thanks for your excellent comments and the useful patch. 
I wasn't aware of vpcc.c file. 
I will wait for your vpcc patch to be pushed, after which I will rework this patch.
>
> > +    if (picture_size <= 0) {
> > +        goto error;
> > +    } else if (picture_size <= 36864) {
> > +        level = 0x10;
> > +    } else if (picture_size <= 73728) {
> > +        level = 0x11;
> > +    } else if (picture_size <= 122880) {
> > +        level = 0x20;
> > +    } else if (picture_size <= 245760) {
> > +        level = 0x21;
> > +    } else if (picture_size <= 552960) {
> > +        level = 0x30;
> > +    } else if (picture_size <= 983040) {
> > +        level = 0x31;
> > +    } else if (picture_size <= 2228224) {
> > +        level = 0x40;
> > +    } else if (picture_size <= 8912896) {
> > +        level = 0x50;
> > +    } else if (picture_size <= 35651584) {
> > +        level = 0x60;
> > +    } else {
> > +        goto error;
> > +    }
> > +    av_strlcatf(str, size, "vp09.%02x.%02x.%02x", profile, level, bitdepth);
> > +    return;
> > +error:
> > +    // Default to just vp9 in case of error while finding out profile or level
> > +    av_strlcpy(str, "vp9", size);
> > +    return;
> > +}
> >  static void set_codec_str(AVFormatContext *s, AVCodecParameters *par,
> >                            char *str, int size)
> >  {
> > @@ -180,7 +253,11 @@ static void set_codec_str(AVFormatContext *s, AVCodecParameters *par,
> >      // common Webm codecs are not part of RFC 6381
> >      for (i = 0; codecs[i].id; i++)
> >          if (codecs[i].id == par->codec_id) {
> > -            av_strlcpy(str, codecs[i].str, size);
> > +            if (codecs[i].id == AV_CODEC_ID_VP9) {
> > +                set_vp9_codec_str(par, str, size);
> > +            } else {
> > +                av_strlcpy(str, codecs[i].str, size);
> > +            }
> >              return;
> >          }
> >  
> > 
>
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