[FFmpeg-devel] [PATCH] avcodec/vp9_parser: export profile and pixel format

[Chris Cunningham]

On Wed, Oct 3, 2018 at 10:49 AM James Almer <jamrial at gmail.com> wrote:

> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>  libavcodec/vp9_parser.c | 82 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 80 insertions(+), 2 deletions(-)
>
> diff --git a/libavcodec/vp9_parser.c b/libavcodec/vp9_parser.c
> index 9531f34a32..d4110f20bf 100644
> --- a/libavcodec/vp9_parser.c
> +++ b/libavcodec/vp9_parser.c
> @@ -23,36 +23,114 @@
>
>  #include "libavutil/intreadwrite.h"
>  #include "libavcodec/get_bits.h"
> +#include "libavcodec/internal.h"
>  #include "parser.h"
>
> +#define VP9_SYNCCODE 0x498342
> +
> +static int read_colorspace_details(AVCodecParserContext *ctx,
> AVCodecContext *avctx,
> +                                   GetBitContext *gb)
> +{
> +    static const enum AVColorSpace colorspaces[8] = {
> +        AVCOL_SPC_UNSPECIFIED, AVCOL_SPC_BT470BG, AVCOL_SPC_BT709,
> AVCOL_SPC_SMPTE170M,
> +        AVCOL_SPC_SMPTE240M, AVCOL_SPC_BT2020_NCL, AVCOL_SPC_RESERVED,
> AVCOL_SPC_RGB,
> +    };
> +    int colorspace, bits = avctx->profile <= 1 ? 0 : 1 + get_bits1(gb);
> // 0:8, 1:10, 2:12
> +
> +    colorspace = colorspaces[get_bits(gb, 3)];
> +    if (colorspace == AVCOL_SPC_RGB) { // RGB = profile 1
> +        static const enum AVPixelFormat pix_fmt_rgb[3] = {
> +            AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP10, AV_PIX_FMT_GBRP12
> +        };
> +        if (avctx->profile & 1) {
> +            if (get_bits1(gb)) // reserved bit
> +                return AVERROR_INVALIDDATA;
> +        } else
> +            return AVERROR_INVALIDDATA;
> +        ctx->format = pix_fmt_rgb[bits];
> +    } else {
> +        static const enum AVPixelFormat pix_fmt_for_ss[3][2 /* v */][2 /*
> h */] = {
> +            { { AV_PIX_FMT_YUV444P,   AV_PIX_FMT_YUV422P },
> +              { AV_PIX_FMT_YUV440P,   AV_PIX_FMT_YUV420P } },
> +            { { AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV422P10 },
> +              { AV_PIX_FMT_YUV440P10, AV_PIX_FMT_YUV420P10 } },
> +            { { AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12 },
> +              { AV_PIX_FMT_YUV440P12, AV_PIX_FMT_YUV420P12 } }
> +        };
> +        if (avctx->profile & 1) {
> +            int ss_h, ss_v, format;
> +
> +            ss_h = get_bits1(gb);
> +            ss_v = get_bits1(gb);
> +            format = pix_fmt_for_ss[bits][ss_v][ss_h];
> +            if (format == AV_PIX_FMT_YUV420P)
> +                // YUV 4:2:0 not supported in profiles 1 and 3
> +                return AVERROR_INVALIDDATA;
> +            else if (get_bits1(gb)) // color details reserved bit
> +                return AVERROR_INVALIDDATA;
> +            ctx->format = format;
> +        } else {
> +            ctx->format = pix_fmt_for_ss[bits][1][1];
> +        }
> +    }
> +
> +    return 0;
> +}
> +
>  static int parse(AVCodecParserContext *ctx,
>                   AVCodecContext *avctx,
>                   const uint8_t **out_data, int *out_size,
>                   const uint8_t *data, int size)
>  {
>      GetBitContext gb;
> -    int res, profile, keyframe;
> +    int res, profile, keyframe, invisible, errorres;
>
>      *out_data = data;
>      *out_size = size;
>
> -    if ((res = init_get_bits8(&gb, data, size)) < 0)
> +    if (!size || (res = init_get_bits8(&gb, data, size)) < 0)
>          return size; // parsers can't return errors
>      get_bits(&gb, 2); // frame marker
>      profile  = get_bits1(&gb);
>      profile |= get_bits1(&gb) << 1;
>      if (profile == 3) profile += get_bits1(&gb);
> +    if (profile > 3)
> +        return size;
>
> +    avctx->profile = profile;
>      if (get_bits1(&gb)) {
>          keyframe = 0;
> +        skip_bits(&gb, 3);
>      } else {
>          keyframe  = !get_bits1(&gb);
>      }
>
> +    invisible = !get_bits1(&gb);
> +    errorres  = get_bits1(&gb);
> +
>      if (!keyframe) {
> +        int intraonly = invisible ? get_bits1(&gb) : 0;
> +        if (!errorres)
> +            skip_bits(&gb, 2);
> +        if (intraonly) {
> +            if (get_bits_long(&gb, 24) != VP9_SYNCCODE) // synccode
> +                return size;
> +            if (profile >= 1) {
> +                if ((read_colorspace_details(ctx, avctx, &gb)) < 0)
> +                    return size;
> +            } else {
> +                ctx->format = AV_PIX_FMT_YUV420P;
> +            }
> +        }
> +
>          ctx->pict_type = AV_PICTURE_TYPE_P;
>          ctx->key_frame = 0;
>      } else {
> +        if (get_bits_long(&gb, 24) != VP9_SYNCCODE) // synccode
> +            return size;
> +        if (read_colorspace_details(ctx, avctx, &gb) < 0)
> +            return size;
> +
>          ctx->pict_type = AV_PICTURE_TYPE_I;
>          ctx->key_frame = 1;
>      }
> --
> 2.19.0
>
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Friendly ping for review.