[FFmpeg-devel] [PATCH] libavfilter/vf_codecview: enable qp visualization for H264 and VP9

Yongle Lin yonglel at google.com
Fri Jul 10 00:18:25 EEST 2020


On Mon, Jul 6, 2020 at 10:56 AM Yongle Lin <yongle.lin.94 at gmail.com> wrote:

>
>
> On Thu, Jun 25, 2020 at 12:09 PM Yongle Lin <yongle.lin.94 at gmail.com>
> wrote:
>
>> Add qp visualization in codecview filter which supports H264 and VP9
>> codecs. Add options for luma/chroma qp and AC/DC qp as well. There is a old
>> way to visualize it but it's deprecated since version 58.
>> example command line to visualize qp:
>> ./ffmpeg -export_side_data +venc_params -i input.mp4 -vf
>> codecview=qp=true output.mp4
>> ---
>>  doc/filters.texi           |  6 ++++
>>  libavfilter/vf_codecview.c | 69 +++++++++++++++++++++++++++++++++++++-
>>  2 files changed, 74 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/filters.texi b/doc/filters.texi
>> index 84567dec16..f4a57e993f 100644
>> --- a/doc/filters.texi
>> +++ b/doc/filters.texi
>> @@ -7285,6 +7285,12 @@ backward predicted MVs of B-frames
>>  @item qp
>>  Display quantization parameters using the chroma planes.
>>
>> + at item chroma_qp
>> +Display chroma quantization parameters (default luma qp) using the
>> chroma planes. Should use with qp option. (e.g.
>> codecview=qp=true:chroma_qp=true)
>> +
>> + at item dc_qp
>> +Display DC quantization parameters (default AC qp) using the chroma
>> planes. Should use with qp option. (e.g. codecview=qp=true:dc_qp=true)
>> +
>>  @item mv_type, mvt
>>  Set motion vectors type to visualize. Includes MVs from all frames
>> unless specified by @var{frame_type} option.
>>
>> diff --git a/libavfilter/vf_codecview.c b/libavfilter/vf_codecview.c
>> index 331bfba777..f585dfe28e 100644
>> --- a/libavfilter/vf_codecview.c
>> +++ b/libavfilter/vf_codecview.c
>> @@ -34,6 +34,7 @@
>>  #include "libavutil/opt.h"
>>  #include "avfilter.h"
>>  #include "internal.h"
>> +#include "libavutil/video_enc_params.h"
>>
>>  #define MV_P_FOR  (1<<0)
>>  #define MV_B_FOR  (1<<1)
>> @@ -51,6 +52,8 @@ typedef struct CodecViewContext {
>>      unsigned mv_type;
>>      int hsub, vsub;
>>      int qp;
>> +    int chroma_qp;
>> +    int dc_qp;
>>  } CodecViewContext;
>>
>>  #define OFFSET(x) offsetof(CodecViewContext, x)
>> @@ -63,6 +66,8 @@ static const AVOption codecview_options[] = {
>>          CONST("bf", "forward predicted MVs of B-frames",  MV_B_FOR,
>> "mv"),
>>          CONST("bb", "backward predicted MVs of B-frames", MV_B_BACK,
>> "mv"),
>>      { "qp", NULL, OFFSET(qp), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags =
>> FLAGS },
>> +    { "chroma_qp", NULL, OFFSET(chroma_qp), AV_OPT_TYPE_BOOL, {.i64=0},
>> 0, 1, .flags = FLAGS },
>> +    { "dc_qp", NULL, OFFSET(dc_qp), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1,
>> .flags = FLAGS },
>>      { "mv_type", "set motion vectors type", OFFSET(mv_type),
>> AV_OPT_TYPE_FLAGS, {.i64=0}, 0, INT_MAX, FLAGS, "mv_type" },
>>      { "mvt",     "set motion vectors type", OFFSET(mv_type),
>> AV_OPT_TYPE_FLAGS, {.i64=0}, 0, INT_MAX, FLAGS, "mv_type" },
>>          CONST("fp", "forward predicted MVs",  MV_TYPE_FOR,  "mv_type"),
>> @@ -212,6 +217,52 @@ static void draw_arrow(uint8_t *buf, int sx, int sy,
>> int ex,
>>      draw_line(buf, sx, sy, ex, ey, w, h, stride, color);
>>  }
>>
>> +static int qp_color_calculate(int qp, enum AVVideoEncParamsType type) {
>> +    return type == AV_VIDEO_ENC_PARAMS_H264 ? qp * 128 / 31 : qp;
>> +}
>> +
>> +static void get_block_color(AVVideoEncParams *par, AVVideoBlockParams
>> *b, CodecViewContext *s, enum AVColorRange color_range, int *cu, int *cv)
>> +{
>> +    const int plane_qp_cu_index = s->chroma_qp ? 1 : 0;
>> +    const int plane_qp_cv_index = s->chroma_qp ? 2 : 0;
>> +    const int ac_dc_index = s->dc_qp ? 0 : 1;
>> +    *cu = qp_color_calculate(par->qp +
>> par->delta_qp[plane_qp_cu_index][ac_dc_index] + b->delta_qp, par->type);
>> +    *cv = qp_color_calculate(par->qp +
>> par->delta_qp[plane_qp_cv_index][ac_dc_index] + b->delta_qp, par->type);
>> +    if (color_range == AVCOL_RANGE_MPEG) {
>> +        // map jpeg color range(0-255) to mpeg color range(16-235)
>> +        *cu = av_rescale(*cu, 73, 85) + 16;
>> +        *cv = av_rescale(*cv, 73, 85) + 16;
>> +    }
>> +}
>> +
>> +static void color_block(AVFrame *frame, CodecViewContext *s, const int
>> src_x, const int src_y, const int b_w, const int b_h, const int cu, const
>> int cv)
>> +{
>> +    const int w = AV_CEIL_RSHIFT(frame->width,  s->hsub);
>> +    const int h = AV_CEIL_RSHIFT(frame->height, s->vsub);
>> +    const int lzu = frame->linesize[1];
>> +    const int lzv = frame->linesize[2];
>> +
>> +    const int plane_src_x = src_x >> s->hsub;
>> +    const int plane_src_y = src_y >> s->vsub;
>> +    const int plane_b_w = b_w >> s->hsub;
>> +    const int plane_b_h = b_h >> s->vsub;
>> +    uint8_t *pu = frame->data[1] + plane_src_y * lzu;
>> +    uint8_t *pv = frame->data[2] + plane_src_y * lzv;
>> +
>> +    for (int y = plane_src_y; y < plane_src_y + plane_b_h; y++) {
>> +        for (int x = plane_src_x; x < plane_src_x + plane_b_w; x++) {
>> +            if (x >= w)
>> +                break;
>> +            pu[x] = cu;
>> +            pv[x] = cv;
>> +        }
>> +        if (y >= h)
>> +            break;
>> +        pu += lzu;
>> +        pv += lzv;
>> +    }
>> +}
>> +
>>  static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
>>  {
>>      AVFilterContext *ctx = inlink->dst;
>> @@ -240,8 +291,24 @@ static int filter_frame(AVFilterLink *inlink,
>> AVFrame *frame)
>>                  pv += lzv;
>>              }
>>          }
>> -    }
>>
>> +        AVFrameSideData *sd = av_frame_get_side_data(frame,
>> AV_FRAME_DATA_VIDEO_ENC_PARAMS);
>> +        if (sd) {
>> +            AVVideoEncParams *par = (AVVideoEncParams*)sd->data;
>> +
>> +            if (par->nb_blocks) {
>> +                for (int i = 0; i < par->nb_blocks; i++) {
>> +                    AVVideoBlockParams *b =
>> av_video_enc_params_block(par, i);
>> +                    int cu, cv;
>> +                    get_block_color(par, b, s, frame->color_range, &cu,
>> &cv);
>> +                    color_block(frame, s, b->src_x, b->src_y, b->w,
>> b->h, cu, cv);
>> +                }
>> +            } else {
>> +                const c = qp_color_calculate(par->qp, par->type);
>> +                color_block(frame, s, 0, 0, frame->width, frame->height,
>> c, c);
>> +            }
>> +        }
>> +    }
>>      if (s->mv || s->mv_type) {
>>          AVFrameSideData *sd = av_frame_get_side_data(frame,
>> AV_FRAME_DATA_MOTION_VECTORS);
>>          if (sd) {
>> --
>> 2.27.0.111.gc72c7da667-goog
>>
>>
> Dear FFmpeg Developers,
>
> Could you please review this patch when you have time. Thanks.
>
> Best,
> Yongle
>

Dear FFmpeg Developers,

I think it is helpful to enable quantization parameters visualization in
FFmpeg. Could you please review this patch, thanks a lot.

Best Regards,
Yongle


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