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lavc, lavu: move frame cropping to a convenience function

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Signed-off-by: Anton Khirnov <anton@khirnov.net>
pull/272/head
wm4 7 years ago committed by Anton Khirnov
parent 80e919b174
commit 47399ccdfd
5 changed files with 140 additions and 88 deletions
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  1. 3
      doc/APIchanges
  2. 89
      libavcodec/decode.c
  3. 100
      libavutil/frame.c
  4. 34
      libavutil/frame.h
  5. 2
      libavutil/version.h

3
doc/APIchanges
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@ -13,6 +13,9 @@ libavutil: 2017-03-23
API changes, most recent first:
2017-xx-xx - xxxxxxx - lavu 56.3.0 - frame.h
Add av_frame_apply_cropping().
2017-xx-xx - xxxxxxx - lavc 58.4.0 - avcodec.h
DXVA2 and D3D11 hardware accelerated decoding now supports the new hwaccel API,
which can create the decoder context and allocate hardware frame automatically.

89
libavcodec/decode.c
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@ -446,44 +446,8 @@ int attribute_align_arg avcodec_send_packet(AVCodecContext *avctx, const AVPacke
return 0;
}
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;
}
static int apply_cropping(AVCodecContext *avctx, AVFrame *frame)
{
const AVPixFmtDescriptor *desc;
size_t offsets[4];
int i;
/* make sure we are noisy about decoders returning invalid cropping data */
if (frame->crop_left >= INT_MAX - frame->crop_right ||
frame->crop_top >= INT_MAX - frame->crop_bottom ||
@ -504,57 +468,8 @@ static int apply_cropping(AVCodecContext *avctx, AVFrame *frame)
if (!avctx->apply_cropping)
return 0;
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 (!(avctx->flags & AV_CODEC_FLAG_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;
return av_frame_apply_cropping(frame, avctx->flags & AV_CODEC_FLAG_UNALIGNED ?
AV_FRAME_CROP_UNALIGNED : 0);
}
int attribute_align_arg avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)

100
libavutil/frame.c
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@ -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;
}

34
libavutil/frame.h
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@ -580,6 +580,40 @@ AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
*/
void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type);
/**
* Flags for frame cropping.
*/
enum {
/**
* Apply the maximum possible cropping, even if it requires setting the
* AVFrame.data[] entries to unaligned pointers. Passing unaligned data
* to Libav API is generally not allowed, and causes undefined behavior
* (such as crashes). You can pass unaligned data only to Libav APIs that
* are explicitly documented to accept it. Use this flag only if you
* absolutely know what you are doing.
*/
AV_FRAME_CROP_UNALIGNED = 1 << 0,
};
/**
* Crop the given video AVFrame according to its crop_left/crop_top/crop_right/
* crop_bottom fields. If cropping is successful, the function will adjust the
* data pointers and the width/height fields, and set the crop fields to 0.
*
* In all cases, the cropping boundaries will be rounded to the inherent
* alignment of the pixel format. In some cases, such as for opaque hwaccel
* formats, the left/top cropping is ignored. The crop fields are set to 0 even
* if the cropping was rounded or ignored.
*
* @param frame the frame which should be cropped
* @param flags Some combination of AV_FRAME_CROP_* flags, or 0.
*
* @return >= 0 on success, a negative AVERROR on error. If the cropping fields
* were invalid, AVERROR(ERANGE) is returned, and nothing is changed.
*/
int av_frame_apply_cropping(AVFrame *frame, int flags);
/**
* @}
*/

2
libavutil/version.h
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@ -54,7 +54,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 56
#define LIBAVUTIL_VERSION_MINOR 2
#define LIBAVUTIL_VERSION_MINOR 3
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

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