[FFmpeg-devel] [PATCH v3] avfilter/vf_showinfo: Fix erroneous results for mean and stdev with pixel bits >8
Limin Wang
lance.lmwang at gmail.com
Mon Jan 6 03:33:12 EET 2020
ping, please review it. I'll add packed format support after that.
On Fri, Nov 29, 2019 at 07:28:23PM +0800, lance.lmwang at gmail.com wrote:
> From: Limin Wang <lance.lmwang at gmail.com>
>
> Have tested with be and le pixel format on be and le system for >8bit.
> System:
> lmwang at ubuntu:~/ffmpeg.git.mips$ grep HAVE_BIGENDIAN config.h
> #define HAVE_BIGENDIAN 1
> ffmpeg.git git:(showinfo) ✗ grep HAVE_BIGENDIAN config.h
> #define HAVE_BIGENDIAN 0
>
> Test result:
> 1, yuv420p
> ./ffmpeg -f lavfi -i color=black:duration=1:r=1:size=1280x720,format=yuv420p,showinfo
> Master:
> mean:[16 128 128] stdev:[0.0 0.0 0.0]
> After applied the patch:
> mean:[16 128 128] stdev:[0.0 0.0 0.0]
>
> 2, yuv420p10le
> ./ffmpeg -f lavfi -i color=black:duration=1:r=1:size=1280x720,format=yuv420p10le,showinfo
> Master:
> mean:[32 1 1] stdev:[32.0 1.0 1.0]
> After applied the patch:
> mean:[64 512 512] stdev:[0.0 0.0 0.0]
>
> 3, yuv420p10be
> ./ffmpeg -f lavfi -i color=black:duration=1:r=1:size=1280x720,format=yuv420p10be,showinfo
> Master:
> mean:[32 1 1] stdev:[32.0 1.0 1.0]
> After applied the patch:
> mean:[64 512 512] stdev:[0.0 0.0 0.0]
>
>
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
> libavfilter/vf_showinfo.c | 34 +++++++++++++++++++++++++++++++---
> 1 file changed, 31 insertions(+), 3 deletions(-)
>
> diff --git a/libavfilter/vf_showinfo.c b/libavfilter/vf_showinfo.c
> index 31f6b32aa4..5856722122 100644
> --- a/libavfilter/vf_showinfo.c
> +++ b/libavfilter/vf_showinfo.c
> @@ -24,6 +24,7 @@
>
> #include <inttypes.h>
>
> +#include "libavutil/bswap.h"
> #include "libavutil/adler32.h"
> #include "libavutil/display.h"
> #include "libavutil/imgutils.h"
> @@ -202,7 +203,7 @@ static void dump_color_property(AVFilterContext *ctx, AVFrame *frame)
> av_log(ctx, AV_LOG_INFO, "\n");
> }
>
> -static void update_sample_stats(const uint8_t *src, int len, int64_t *sum, int64_t *sum2)
> +static void update_sample_stats_8(const uint8_t *src, int len, int64_t *sum, int64_t *sum2)
> {
> int i;
>
> @@ -212,6 +213,30 @@ static void update_sample_stats(const uint8_t *src, int len, int64_t *sum, int64
> }
> }
>
> +static void update_sample_stats_16(int be, const uint8_t *src, int len, int64_t *sum, int64_t *sum2)
> +{
> + const uint16_t *src1 = (const uint16_t *)src;
> + int i;
> +
> + for (i = 0; i < len / 2; i++) {
> + if ((HAVE_BIGENDIAN && !be) || (!HAVE_BIGENDIAN && be)) {
> + *sum += av_bswap16(src1[i]);
> + *sum2 += av_bswap16(src1[i]) * av_bswap16(src1[i]);
> + } else {
> + *sum += src1[i];
> + *sum2 += src1[i] * src1[i];
> + }
> + }
> +}
> +
> +static void update_sample_stats(int depth, int be, const uint8_t *src, int len, int64_t *sum, int64_t *sum2)
> +{
> + if (depth <= 8)
> + update_sample_stats_8(src, len, sum, sum2);
> + else
> + update_sample_stats_16(be, src, len, sum, sum2);
> +}
> +
> static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
> {
> AVFilterContext *ctx = inlink->dst;
> @@ -220,12 +245,15 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
> uint32_t plane_checksum[4] = {0}, checksum = 0;
> int64_t sum[4] = {0}, sum2[4] = {0};
> int32_t pixelcount[4] = {0};
> + int bitdepth = desc->comp[0].depth;
> + int be = desc->flags & AV_PIX_FMT_FLAG_BE;
> int i, plane, vsub = desc->log2_chroma_h;
>
> for (plane = 0; plane < 4 && s->calculate_checksums && frame->data[plane] && frame->linesize[plane]; plane++) {
> uint8_t *data = frame->data[plane];
> int h = plane == 1 || plane == 2 ? AV_CEIL_RSHIFT(inlink->h, vsub) : inlink->h;
> int linesize = av_image_get_linesize(frame->format, frame->width, plane);
> + int width = linesize >> (bitdepth > 8);
>
> if (linesize < 0)
> return linesize;
> @@ -234,8 +262,8 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
> plane_checksum[plane] = av_adler32_update(plane_checksum[plane], data, linesize);
> checksum = av_adler32_update(checksum, data, linesize);
>
> - update_sample_stats(data, linesize, sum+plane, sum2+plane);
> - pixelcount[plane] += linesize;
> + update_sample_stats(bitdepth, be, data, linesize, sum+plane, sum2+plane);
> + pixelcount[plane] += width;
> data += frame->linesize[plane];
> }
> }
> --
> 2.21.0
>
--
Thanks,
Limin Wang
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