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[FFmpeg-devel] hw_base_enc: inject side data to crop output for AV1

Message ID 20240914062856.132625-1-dev@lynne.ee
State New
Headers show
Series [FFmpeg-devel] hw_base_enc: inject side data to crop output for AV1 | expand

Checks

Context Check Description
andriy/make_x86 fail Make failed
yinshiyou/make_loongarch64 fail Make failed

Commit Message

Lynne Sept. 14, 2024, 6:28 a.m. UTC 
Unlike H264/H265, AV1 contains no fields to crop encoded output
to specific sizes.
AMD's hardware cannot handle encoding of unaligned dimensions for
AV1, hence it codes 1920x1080 as 1920x1088.

Add side data to crop the output back to the original dimensions.
There's an AV1-spec extension planned to fix this here:
https://github.com/AOMediaCodec/av1-spec/pull/346

But it seems to have stuck for now.
---
 libavcodec/hw_base_encode.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
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Patch

diff --git a/libavcodec/hw_base_encode.c b/libavcodec/hw_base_encode.c
index 7b6ec97d3b..6e67c9c301 100644
--- a/libavcodec/hw_base_encode.c
+++ b/libavcodec/hw_base_encode.c
@@ -22,6 +22,7 @@ 
 #include "libavutil/log.h"
 #include "libavutil/mem.h"
 #include "libavutil/pixdesc.h"
+#include "libavutil/intreadwrite.h"
 
 #include "encode.h"
 #include "avcodec.h"
@@ -551,6 +552,30 @@  int ff_hw_base_encode_set_output_property(FFHWBaseEncodeContext *ctx,
                                 (3 * ctx->output_delay + ctx->async_depth)];
     }
 
+    if ((avctx->codec_id == AV_CODEC_ID_AV1) &&
+        ((avctx->coded_width != avctx->width) ||
+         (avctx->coded_height != avctx->height)) {
+        int err;
+        size_t crop_data_size = 4*4;
+
+        uint8_t *crop_data = av_mallocz(crop_data_size);
+        if (!crop_data) {
+            av_buffer_unref(&pkt->buf);
+            return AVERROR(ENOMEM);
+        }
+
+        AV_WL32(&crop_data[2], ctx->surface_width - avctx->width);
+        AV_WL32(&crop_data[3], ctx->surface_height - avctx->height);
+
+        err = av_packet_add_side_data(pkt, AV_PKT_DATA_FRAME_CROPPING,
+                                      crop_data, crop_data_size);
+        if (err < 0) {
+            av_buffer_unref(&pkt->buf);
+            av_free(crop_data);
+            return err;
+        }
+    }
+
     return 0;
 }