[FFmpeg-devel] [crop support for matroska demuxer 2/3] libavcodec: Public code to support container crop

[OvchinnikovDmitrii]

Support both simple and receive_frame api
The container crop information is applied additional to frame crop information
---
 libavcodec/codec_par.c |  8 ++++++++
 libavcodec/decode.c    | 20 ++++++++++++++++++++
 2 files changed, 28 insertions(+)

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/decode.c b/libavcodec/decode.c
index 6be2d3d6ed..548225c904 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -324,6 +324,16 @@ static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame,
     emms_c();
     actual_got_frame = got_frame;
 
+    /* crop for simple api mode. apply additional container crop info to 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;
@@ -707,6 +717,16 @@ int ff_decode_receive_frame(AVCodecContext *avctx, AVFrame *frame)
 
     if (avci->buffer_frame->buf[0]) {
         av_frame_move_ref(frame, avci->buffer_frame);
+
+        /* crop for receive_frame api mode. apply additional container crop info to 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;
+            }
+        }
     } else {
         ret = decode_receive_frame_internal(avctx, frame);
         if (ret < 0)
-- 
2.30.0.windows.2