[FFmpeg-devel] [PATCH v2 4/9] vp9_parser: Return stream properties

[Li, Zhong]

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of Mark Thompson
> Sent: Tuesday, April 2, 2019 7:40 AM
> To: ffmpeg-devel at ffmpeg.org
> Subject: [FFmpeg-devel] [PATCH v2 4/9] vp9_parser: Return stream
> properties
> 
> Rewrites the parser entirely, using CBS for header parsing.
> ---
>  libavcodec/vp9_parser.c | 112 +++++++++++++++++++++++++++++-----------
>  1 file changed, 82 insertions(+), 30 deletions(-)
> 
> diff --git a/libavcodec/vp9_parser.c b/libavcodec/vp9_parser.c index
> c957a75667..6bf4f30e80 100644
> --- a/libavcodec/vp9_parser.c
> +++ b/libavcodec/vp9_parser.c
> @@ -1,8 +1,5 @@
>  /*
> - * VP9 compatible video decoder
> - *
> - * Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com>
> - * Copyright (C) 2013 Clément Bœsch <u pkh me>
> + * VP9 parser
>   *
>   * This file is part of FFmpeg.
>   *
> @@ -21,50 +18,105 @@
>   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
> USA
>   */
> 
> -#include "libavutil/intreadwrite.h"
> -#include "libavcodec/get_bits.h"
> +#include "libavutil/avassert.h"
> +#include "cbs.h"
> +#include "cbs_vp9.h"
>  #include "parser.h"
> 
> -static int parse(AVCodecParserContext *ctx,
> -                 AVCodecContext *avctx,
> -                 const uint8_t **out_data, int *out_size,
> -                 const uint8_t *data, int size)
> +typedef struct VP9ParserContext {
> +    CodedBitstreamContext *cbc;
> +    VP9RawFrameHeader frame_header;
> +} VP9ParserContext;
> +
> +static const enum AVPixelFormat vp9_pix_fmts[3][2][2] = {
> +    { // 8-bit.
> +        { AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P },
> +        { AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P },
> +    },
> +    { // 10-bit.
> +        { AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV440P10 },
> +        { AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV420P10 },
> +    },
> +    { // 12-bit.
> +        { AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12 },
> +        { AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12 },
> +    },
> +};
> +
> +static int vp9_parser_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;
> +    VP9ParserContext *s = ctx->priv_data;
> +    const CodedBitstreamVP9Context *vp9 = s->cbc->priv_data;
> +    const VP9RawFrameHeader *fh;
> +    int err;
> 
>      *out_data = data;
>      *out_size = size;
> 
> -    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;
> +    ctx->key_frame         = -1;
> +    ctx->pict_type         = AV_PICTURE_TYPE_NONE;
> +    ctx->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
> 
> -    avctx->profile = profile;
> +    if (!size)
> +        return 0;
> 
> -    if (get_bits1(&gb)) {
> -        keyframe = 0;
> -    } else {
> -        keyframe  = !get_bits1(&gb);
> +    s->cbc->log_ctx = avctx;
> +
> +    err = ff_cbs_parse_headers(s->cbc, &s->frame_header, data, size);
> +    if (err < 0) {
> +        av_log(avctx, AV_LOG_WARNING, "Failed to parse VP9 frame
> headers.\n");
> +        goto end;
>      }
> +    fh = &s->frame_header;
> 
> -    if (!keyframe) {
> -        ctx->pict_type = AV_PICTURE_TYPE_P;
> -        ctx->key_frame = 0;
> -    } else {
> +    avctx->profile = vp9->profile;
> +    avctx->level   = FF_LEVEL_UNKNOWN;
> +
> +    ctx->width  = ctx->coded_width  = vp9->frame_width;
> +    ctx->height = ctx->coded_height = vp9->frame_height;
> +
> +    if (fh->frame_type == VP9_KEY_FRAME) {
>          ctx->pict_type = AV_PICTURE_TYPE_I;
>          ctx->key_frame = 1;
> +    } else {
> +        ctx->pict_type = fh->intra_only ? AV_PICTURE_TYPE_I :
> AV_PICTURE_TYPE_P;
> +        ctx->key_frame = 0;
>      }
> 
> +    ctx->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
> +
> +    av_assert0(vp9->bit_depth == 8  ||
> +               vp9->bit_depth == 10 ||
> +               vp9->bit_depth == 12);
> +
> +    ctx->format = vp9_pix_fmts[(vp9->bit_depth - 8) / 2]
> +
> [vp9->subsampling_x][vp9->subsampling_y];
> +
> +end:
> +    s->cbc->log_ctx = NULL;
> +
>      return size;
>  }
> 
> +static av_cold int vp9_parser_init(AVCodecParserContext *ctx) {
> +    VP9ParserContext *s = ctx->priv_data;
> +    return ff_cbs_init(&s->cbc, AV_CODEC_ID_VP9, NULL); }
> +
> +static av_cold void vp9_parser_close(AVCodecParserContext *ctx) {
> +    VP9ParserContext *s = ctx->priv_data;
> +    ff_cbs_close(&s->cbc);
> +}
> +
>  AVCodecParser ff_vp9_parser = {
>      .codec_ids      = { AV_CODEC_ID_VP9 },
> -    .parser_parse   = parse,
> +    .priv_data_size = sizeof(VP9ParserContext),
> +    .parser_init    = &vp9_parser_init,
> +    .parser_close   = &vp9_parser_close,
> +    .parser_parse   = &vp9_parser_parse,
>  };
> --
> 2.20.1

LGTM