[FFmpeg-devel] [PATCH] libavformat\matroskadec.c: crop support for matroska demuxer.
OvchinnikovDmitrii
ovchinnikov.dmitrii at gmail.com
Wed Sep 21 14:29:05 EEST 2022
In webm specification, it supports cropping information. (https://www.webmproject.org/docs/container/)
In ffmpeg, the implementation of webm is a subset of matroska. In matroskadec.c, those cropping related four fields are forced to 0.
for the sample file with crop (crop_bottom =8, crop_top=crop_left=crop_right=0.)
ffmpeg.exe -i test_with_container_crop.webm -pix_fmt yuv420p -y output.yuv
original ffmpeg code - the output.yuv resolution is 1920x1088
changed code - the output.yuv resolution is 1920x1080"
---
libavcodec/avcodec.h | 8 ++++++++
libavcodec/codec_par.c | 8 ++++++++
libavcodec/codec_par.h | 8 ++++++++
libavcodec/decode.c | 9 +++++++++
libavformat/matroskadec.c | 17 +++++++++++++----
5 files changed, 46 insertions(+), 4 deletions(-)
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 7db5d1b1c5..4420cfa0c9 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -585,6 +585,14 @@ typedef struct AVCodecContext {
*/
int coded_width, coded_height;
+ /**
+ * The dimensions of the crop, usually from container.
+ */
+ int crop_top;
+ int crop_left;
+ int crop_bottom;
+ int crop_right;
+
/**
* the number of pictures in a group of pictures, or 0 for intra_only
* - encoding: Set by user.
diff --git a/libavcodec/codec_par.c b/libavcodec/codec_par.c
index abda649aa8..f74964a817 100644
--- a/libavcodec/codec_par.c
+++ b/libavcodec/codec_par.c
@@ -118,6 +118,10 @@ int avcodec_parameters_from_context(AVCodecParameters *par,
par->format = codec->pix_fmt;
par->width = codec->width;
par->height = codec->height;
+ par->crop_top = codec->crop_top;
+ par->crop_left = codec->crop_left;
+ par->crop_bottom = codec->crop_bottom;
+ par->crop_right = codec->crop_right;
par->field_order = codec->field_order;
par->color_range = codec->color_range;
par->color_primaries = codec->color_primaries;
@@ -199,6 +203,10 @@ int avcodec_parameters_to_context(AVCodecContext *codec,
codec->pix_fmt = par->format;
codec->width = par->width;
codec->height = par->height;
+ codec->crop_top = par->crop_top;
+ codec->crop_left = par->crop_left;
+ codec->crop_bottom = par->crop_bottom;
+ codec->crop_right = par->crop_right;
codec->field_order = par->field_order;
codec->color_range = par->color_range;
codec->color_primaries = par->color_primaries;
diff --git a/libavcodec/codec_par.h b/libavcodec/codec_par.h
index 7660791a12..6671f1810b 100644
--- a/libavcodec/codec_par.h
+++ b/libavcodec/codec_par.h
@@ -127,6 +127,14 @@ typedef struct AVCodecParameters {
int width;
int height;
+ /**
+ * The dimensions of the crop, usually from container.
+ */
+ int crop_top;
+ int crop_left;
+ int crop_bottom;
+ int crop_right;
+
/**
* Video only. The aspect ratio (width / height) which a single pixel
* should have when displayed.
diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index 2961705c9d..905eb8401e 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -324,6 +324,15 @@ static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame,
emms_c();
actual_got_frame = got_frame;
+ if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
+ if (avctx->crop_top != 0 || avctx->crop_left != 0 || avctx->crop_right != 0 || avctx->crop_bottom != 0){
+ frame->crop_top = avctx->crop_top;
+ frame->crop_left = avctx->crop_left;
+ frame->crop_right = avctx->crop_right;
+ frame->crop_bottom = avctx->crop_bottom;
+ }
+ }
+
if (avctx->codec->type == AVMEDIA_TYPE_VIDEO) {
if (frame->flags & AV_FRAME_FLAG_DISCARD)
got_frame = 0;
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 16a3e93611..6e05b36e58 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -209,6 +209,10 @@ typedef struct MatroskaTrackVideo {
uint64_t pixel_width;
uint64_t pixel_height;
EbmlBin color_space;
+ uint64_t pixel_cropt;
+ uint64_t pixel_cropl;
+ uint64_t pixel_cropb;
+ uint64_t pixel_cropr;
uint64_t display_unit;
uint64_t interlaced;
uint64_t field_order;
@@ -516,10 +520,10 @@ static EbmlSyntax matroska_track_video[] = {
{ MATROSKA_ID_VIDEOALPHAMODE, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, alpha_mode), { .u = 0 } },
{ MATROSKA_ID_VIDEOCOLOR, EBML_NEST, 0, sizeof(MatroskaTrackVideoColor), offsetof(MatroskaTrackVideo, color), { .n = matroska_track_video_color } },
{ MATROSKA_ID_VIDEOPROJECTION, EBML_NEST, 0, 0, offsetof(MatroskaTrackVideo, projection), { .n = matroska_track_video_projection } },
- { MATROSKA_ID_VIDEOPIXELCROPB, EBML_NONE },
- { MATROSKA_ID_VIDEOPIXELCROPT, EBML_NONE },
- { MATROSKA_ID_VIDEOPIXELCROPL, EBML_NONE },
- { MATROSKA_ID_VIDEOPIXELCROPR, EBML_NONE },
+ { MATROSKA_ID_VIDEOPIXELCROPT, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, pixel_cropt), {.u = 0 } },
+ { MATROSKA_ID_VIDEOPIXELCROPL, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, pixel_cropl), {.u = 0 } },
+ { MATROSKA_ID_VIDEOPIXELCROPB, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, pixel_cropb), {.u = 0 } },
+ { MATROSKA_ID_VIDEOPIXELCROPR, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, pixel_cropr), {.u = 0 } },
{ MATROSKA_ID_VIDEODISPLAYUNIT, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, display_unit), { .u= MATROSKA_VIDEO_DISPLAYUNIT_PIXELS } },
{ MATROSKA_ID_VIDEOFLAGINTERLACED, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, interlaced), { .u = MATROSKA_VIDEO_INTERLACE_FLAG_UNDETERMINED } },
{ MATROSKA_ID_VIDEOFIELDORDER, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideo, field_order), { .u = MATROSKA_VIDEO_FIELDORDER_UNDETERMINED } },
@@ -2878,6 +2882,11 @@ static int matroska_parse_tracks(AVFormatContext *s)
st->codecpar->width = track->video.pixel_width;
st->codecpar->height = track->video.pixel_height;
+ st->codecpar->crop_top = track->video.pixel_cropt;
+ st->codecpar->crop_left = track->video.pixel_cropl;
+ st->codecpar->crop_bottom= track->video.pixel_cropb;
+ st->codecpar->crop_right = track->video.pixel_cropr;
+
if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_INTERLACED)
st->codecpar->field_order = mkv_field_order(matroska, track->video.field_order);
else if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_PROGRESSIVE)
--
2.30.0.windows.2
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