ffmpeg | branch: master | Niklas Haas <g...@haasn.dev> | Thu Jun 12 16:43:24 2025 +0200| [cf18b280f0f4f602794163c917dd595220fb99b6] | committer: Niklas Haas
avfilter/vf_thumbnail: support more planar formats This adds support for high bit depth formats, as well as formats with fewer than 3 planes. The implementation for HBD is the same as for 8 bit formats, just right shifted to 8 bits. It's worth pointing out that this also works for HDR formats (and even DV), because the underlying implementation is just trying to minimize the histogram difference. If anything, using a HDR format will result in a *more* accurate detection, because HDR formats tend to be more perceptually uniform. > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cf18b280f0f4f602794163c917dd595220fb99b6 --- libavfilter/vf_thumbnail.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/libavfilter/vf_thumbnail.c b/libavfilter/vf_thumbnail.c index 90125a879c..55a0598e50 100644 --- a/libavfilter/vf_thumbnail.c +++ b/libavfilter/vf_thumbnail.c @@ -53,6 +53,8 @@ typedef struct ThumbContext { int planewidth[4]; int planeheight[4]; + int planes; + int bitdepth; } ThumbContext; #define OFFSET(x) offsetof(ThumbContext, x) @@ -194,7 +196,7 @@ static int do_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) } break; default: - for (int plane = 0; plane < 3; plane++) { + for (int plane = 0; plane < s->planes; plane++) { const int slice_start = (s->planeheight[plane] * jobnr) / nb_jobs; const int slice_end = (s->planeheight[plane] * (jobnr+1)) / nb_jobs; const uint8_t *p = frame->data[plane] + slice_start * frame->linesize[plane]; @@ -202,10 +204,21 @@ static int do_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) const int planewidth = s->planewidth[plane]; int *hhist = hist + 256 * plane; - for (int j = slice_start; j < slice_end; j++) { - for (int i = 0; i < planewidth; i++) - hhist[p[i]]++; - p += linesize; + if (s->bitdepth > 8) { + const uint16_t *p16 = (const uint16_t *) p; + const int shift = s->bitdepth - 8; + + for (int j = slice_start; j < slice_end; j++) { + for (int i = 0; i < planewidth; i++) + hhist[(p16[i] >> shift) & 0xFF]++; + p16 += linesize >> 1; + } + } else { + for (int j = slice_start; j < slice_end; j++) { + for (int i = 0; i < planewidth; i++) + hhist[p[i]]++; + p += linesize; + } } } break; @@ -286,6 +299,8 @@ static int config_props(AVFilterLink *inlink) s->planewidth[0] = s->planewidth[3] = inlink->w; s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h); s->planeheight[0] = s->planeheight[3] = inlink->h; + s->planes = av_pix_fmt_count_planes(inlink->format) - !!(desc->flags & AV_PIX_FMT_FLAG_ALPHA); + s->bitdepth = desc->comp[0].depth; return 0; } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
