diff options
author | wm4 <nfxjfg@googlemail.com> | 2017-07-23 00:05:13 +0300 |
---|---|---|
committer | Anton Khirnov <anton@khirnov.net> | 2017-07-27 00:20:40 +0300 |
commit | 47399ccdfd93d337c96c76fbf591f0e3637131ef (patch) | |
tree | ae06fa9d96723576f36185137056e509f67f17ee /libavutil/frame.c | |
parent | 80e919b17435da18c0f2be6403a0315cf4b40a1a (diff) |
lavc, lavu: move frame cropping to a convenience function
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Diffstat (limited to 'libavutil/frame.c')
-rw-r--r-- | libavutil/frame.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/libavutil/frame.c b/libavutil/frame.c index 9cd5f9ab37..db3897c299 100644 --- a/libavutil/frame.c +++ b/libavutil/frame.c @@ -596,3 +596,103 @@ void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type) } } } + +static int calc_cropping_offsets(size_t offsets[4], const AVFrame *frame, + const AVPixFmtDescriptor *desc) +{ + int i, j; + + for (i = 0; frame->data[i]; i++) { + const AVComponentDescriptor *comp = NULL; + int shift_x = (i == 1 || i == 2) ? desc->log2_chroma_w : 0; + int shift_y = (i == 1 || i == 2) ? desc->log2_chroma_h : 0; + + if (desc->flags & (AV_PIX_FMT_FLAG_PAL | AV_PIX_FMT_FLAG_PSEUDOPAL) && i == 1) { + offsets[i] = 0; + break; + } + + /* find any component descriptor for this plane */ + for (j = 0; j < desc->nb_components; j++) { + if (desc->comp[j].plane == i) { + comp = &desc->comp[j]; + break; + } + } + if (!comp) + return AVERROR_BUG; + + offsets[i] = (frame->crop_top >> shift_y) * frame->linesize[i] + + (frame->crop_left >> shift_x) * comp->step; + } + + return 0; +} + +int av_frame_apply_cropping(AVFrame *frame, int flags) +{ + const AVPixFmtDescriptor *desc; + size_t offsets[4]; + int i; + + if (!(frame->width > 0 && frame->height > 0)) + return AVERROR(EINVAL); + + if (frame->crop_left >= INT_MAX - frame->crop_right || + frame->crop_top >= INT_MAX - frame->crop_bottom || + (frame->crop_left + frame->crop_right) >= frame->width || + (frame->crop_top + frame->crop_bottom) >= frame->height) + return AVERROR(ERANGE); + + desc = av_pix_fmt_desc_get(frame->format); + if (!desc) + return AVERROR_BUG; + + /* Apply just the right/bottom cropping for hwaccel formats. Bitstream + * formats cannot be easily handled here either (and corresponding decoders + * should not export any cropping anyway), so do the same for those as well. + * */ + if (desc->flags & (AV_PIX_FMT_FLAG_BITSTREAM | AV_PIX_FMT_FLAG_HWACCEL)) { + frame->width -= frame->crop_right; + frame->height -= frame->crop_bottom; + frame->crop_right = 0; + frame->crop_bottom = 0; + return 0; + } + + /* calculate the offsets for each plane */ + calc_cropping_offsets(offsets, frame, desc); + + /* adjust the offsets to avoid breaking alignment */ + if (!(flags & AV_FRAME_CROP_UNALIGNED)) { + int log2_crop_align = frame->crop_left ? av_ctz(frame->crop_left) : INT_MAX; + int min_log2_align = INT_MAX; + + for (i = 0; frame->data[i]; i++) { + int log2_align = offsets[i] ? av_ctz(offsets[i]) : INT_MAX; + min_log2_align = FFMIN(log2_align, min_log2_align); + } + + /* we assume, and it should always be true, that the data alignment is + * related to the cropping alignment by a constant power-of-2 factor */ + if (log2_crop_align < min_log2_align) + return AVERROR_BUG; + + if (min_log2_align < 5) { + frame->crop_left &= ~((1 << (5 + log2_crop_align - min_log2_align)) - 1); + calc_cropping_offsets(offsets, frame, desc); + } + } + + for (i = 0; frame->data[i]; i++) + frame->data[i] += offsets[i]; + + frame->width -= (frame->crop_left + frame->crop_right); + frame->height -= (frame->crop_top + frame->crop_bottom); + frame->crop_left = 0; + frame->crop_right = 0; + frame->crop_top = 0; + frame->crop_bottom = 0; + + return 0; +} |