avutil/imgutils: Add wrapper for av_image_copy() to avoid casts

av_image_copy() accepts const uint8_t* const * as source;
lots of user have uint8_t* const * and therefore either
cast (the majority) or copy the array of pointers.

This commit changes this by adding a static inline wrapper
for av_image_copy() that casts between the two types
so that we do not need to add casts everywhere else.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

doc/APIchanges

@@ -2,6 +2,10 @@ The last version increases of all libraries were on 2023-02-09
 
 API changes, most recent first:
 
+2023-09-07 - xxxxxxxxxx - lavu 58.24.100 - imgutils.h
+  Add av_image_copy2(), a wrapper around the av_image_copy()
+  to overcome limitations of automatic conversions.
+
 2023-09-07 - xxxxxxxxxx - lavu 58.23.100 - fifo.h
   Constify the AVFifo pointees in av_fifo_peek() and av_fifo_peek_to_cb().
 

doc/examples/demux_decode.c

@@ -78,9 +78,9 @@ static int output_video_frame(AVFrame *frame)
 
     /* copy decoded frame to destination buffer:
      * this is required since rawvideo expects non aligned data */
-    av_image_copy(video_dst_data, video_dst_linesize,
-                  (const uint8_t **)(frame->data), frame->linesize,
-                  pix_fmt, width, height);
+    av_image_copy2(video_dst_data, video_dst_linesize,
+                   frame->data, frame->linesize,
+                   pix_fmt, width, height);
 
     /* write to rawvideo file */
     fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);

libavcodec/amfenc.c

@@ -430,9 +430,9 @@ static int amf_copy_surface(AVCodecContext *avctx, const AVFrame *frame,
         dst_data[i] = plane->pVtbl->GetNative(plane);
         dst_linesize[i] = plane->pVtbl->GetHPitch(plane);
     }
-    av_image_copy(dst_data, dst_linesize,
-        (const uint8_t**)frame->data, frame->linesize, frame->format,
-        avctx->width, avctx->height);
+    av_image_copy2(dst_data, dst_linesize,
+                   frame->data, frame->linesize, frame->format,
+                   avctx->width, avctx->height);
 
     return 0;
 }

libavcodec/libkvazaar.c

@@ -221,9 +221,9 @@ static int libkvazaar_encode(AVCodecContext *avctx,
               frame->width / 2,
               0
             };
-            av_image_copy(dst, dst_linesizes,
-                          (const uint8_t **)frame->data, frame->linesize,
-                          frame->format, frame->width, frame->height);
+            av_image_copy2(dst, dst_linesizes,
+                           frame->data, frame->linesize,
+                           frame->format, frame->width, frame->height);
         }
 
         input_pic->pts = frame->pts;

libavcodec/libopenh264dec.c

@@ -141,7 +141,8 @@ static int svc_decode_frame(AVCodecContext *avctx, AVFrame *avframe,
     linesize[0] = info.UsrData.sSystemBuffer.iStride[0];
     linesize[1] = linesize[2] = info.UsrData.sSystemBuffer.iStride[1];
     linesize[3] = 0;
-    av_image_copy(avframe->data, avframe->linesize, (const uint8_t **) ptrs, linesize, avctx->pix_fmt, avctx->width, avctx->height);
+    av_image_copy2(avframe->data, avframe->linesize, ptrs, linesize,
+                   avctx->pix_fmt, avctx->width, avctx->height);
 
     avframe->pts     = info.uiOutYuvTimeStamp;
     avframe->pkt_dts = AV_NOPTS_VALUE;

libavcodec/libvpxdec.c

@@ -329,8 +329,8 @@ static int vpx_decode(AVCodecContext *avctx, AVFrame *picture,
         } else {
             if ((ret = ff_get_buffer(avctx, picture, 0)) < 0)
                 return ret;
-            av_image_copy(picture->data, picture->linesize, (const uint8_t**)planes,
-                          linesizes, avctx->pix_fmt, img->d_w, img->d_h);
+            av_image_copy2(picture->data, picture->linesize, planes,
+                           linesizes, avctx->pix_fmt, img->d_w, img->d_h);
         }
         *got_frame           = 1;
     }

libavcodec/mediacodecenc.c

@@ -428,9 +428,6 @@ static void copy_frame_to_buffer(AVCodecContext *avctx, const AVFrame *frame, ui
     MediaCodecEncContext *s = avctx->priv_data;
     uint8_t *dst_data[4] = {};
     int dst_linesize[4] = {};
-    const uint8_t *src_data[4] = {
-            frame->data[0], frame->data[1], frame->data[2], frame->data[3]
-    };
 
     if (avctx->pix_fmt == AV_PIX_FMT_YUV420P) {
         dst_data[0] = dst;
@@ -449,8 +446,8 @@ static void copy_frame_to_buffer(AVCodecContext *avctx, const AVFrame *frame, ui
         av_assert0(0);
     }
 
-    av_image_copy(dst_data, dst_linesize, src_data, frame->linesize,
-                  avctx->pix_fmt, avctx->width, avctx->height);
+    av_image_copy2(dst_data, dst_linesize, frame->data, frame->linesize,
+                   avctx->pix_fmt, avctx->width, avctx->height);
 }
 
 static int mediacodec_send(AVCodecContext *avctx,

libavcodec/mmaldec.c

@@ -648,8 +648,8 @@ static int ffmal_copy_frame(AVCodecContext *avctx,  AVFrame *frame,
         av_image_fill_arrays(src, linesize,
                              buffer->data + buffer->type->video.offset[0],
                              avctx->pix_fmt, w, h, 1);
-        av_image_copy(frame->data, frame->linesize, (const uint8_t **)src, linesize,
-                      avctx->pix_fmt, avctx->width, avctx->height);
+        av_image_copy2(frame->data, frame->linesize, src, linesize,
+                       avctx->pix_fmt, avctx->width, avctx->height);
     }
 
     frame->sample_aspect_ratio = avctx->sample_aspect_ratio;

libavcodec/nuv.c

@@ -56,8 +56,8 @@ static void copy_frame(AVFrame *f, const uint8_t *src, int width, int height)
     int src_linesize[4];
     av_image_fill_arrays(src_data, src_linesize, src,
                          f->format, width, height, 1);
-    av_image_copy(f->data, f->linesize, (const uint8_t **)src_data, src_linesize,
-                  f->format, width, height);
+    av_image_copy2(f->data, f->linesize, src_data, src_linesize,
+                   f->format, width, height);
 }
 
 /**

libavcodec/nvenc.c

@@ -2008,9 +2008,9 @@ static int nvenc_copy_frame(AVCodecContext *avctx, NvencSurface *nv_surface,
     if (frame->format == AV_PIX_FMT_YUV420P)
         FFSWAP(uint8_t*, dst_data[1], dst_data[2]);
 
-    av_image_copy(dst_data, dst_linesize,
-                  (const uint8_t**)frame->data, frame->linesize, frame->format,
-                  avctx->width, avctx->height);
+    av_image_copy2(dst_data, dst_linesize,
+                   frame->data, frame->linesize, frame->format,
+                   avctx->width, avctx->height);
 
     return 0;
 }

libavcodec/omx.c

@@ -793,7 +793,8 @@ static int omx_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
             need_copy = 1;
         }
         if (need_copy)
-            av_image_copy(dst, linesize, (const uint8_t**) frame->data, frame->linesize, avctx->pix_fmt, avctx->width, avctx->height);
+            av_image_copy2(dst, linesize, frame->data, frame->linesize,
+                           avctx->pix_fmt, avctx->width, avctx->height);
         buffer->nFlags = OMX_BUFFERFLAG_ENDOFFRAME;
         buffer->nOffset = 0;
         // Convert the timestamps to microseconds; some encoders can ignore

libavcodec/v210dec.c

@@ -201,7 +201,8 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *pic,
         if (ret < 0)
             return ret;
         decode_row((const uint32_t *)psrc, (uint16_t *)pointers[0], (uint16_t *)pointers[1], (uint16_t *)pointers[2], avctx->width * avctx->height, s->unpack_frame);
-        av_image_copy(pic->data, pic->linesize, (const uint8_t **)pointers, linesizes, avctx->pix_fmt, avctx->width, avctx->height);
+        av_image_copy2(pic->data, pic->linesize, pointers, linesizes,
+                       avctx->pix_fmt, avctx->width, avctx->height);
         av_freep(&pointers[0]);
     }
 

libavdevice/xv.c

@@ -315,8 +315,8 @@ static int write_picture(AVFormatContext *s, uint8_t *input_data[4],
         }
     }
 
-    av_image_copy(data, img->pitches, (const uint8_t **)input_data, linesize,
-                  xv->image_format, img->width, img->height);
+    av_image_copy2(data, img->pitches, input_data, linesize,
+                   xv->image_format, img->width, img->height);
     return xv_repaint(s);
 }
 

libavfilter/lavfutils.c

@@ -117,7 +117,8 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
         goto end;
     ret = 0;
 
-    av_image_copy(data, linesize, (const uint8_t **)frame->data, frame->linesize, *pix_fmt, *w, *h);
+    av_image_copy2(data, linesize, frame->data, frame->linesize,
+                   *pix_fmt, *w, *h);
 
 end:
     avcodec_free_context(&codec_ctx);

libavfilter/vf_framepack.c

@@ -234,22 +234,18 @@ static void horizontal_frame_pack(AVFilterLink *outlink,
     } else {
         for (i = 0; i < 2; i++) {
             const int psize = 1 + (s->depth > 8);
-            const uint8_t *src[4];
             uint8_t *dst[4];
             int sub_w = psize * s->input_views[i]->width >> s->pix_desc->log2_chroma_w;
 
-            src[0] = s->input_views[i]->data[0];
-            src[1] = s->input_views[i]->data[1];
-            src[2] = s->input_views[i]->data[2];
-
             dst[0] = out->data[0] + i * s->input_views[i]->width * psize;
             dst[1] = out->data[1] + i * sub_w;
             dst[2] = out->data[2] + i * sub_w;
 
-            av_image_copy(dst, out->linesize, src, s->input_views[i]->linesize,
-                          s->input_views[i]->format,
-                          s->input_views[i]->width,
-                          s->input_views[i]->height);
+            av_image_copy2(dst, out->linesize,
+                           s->input_views[i]->data, s->input_views[i]->linesize,
+                           s->input_views[i]->format,
+                           s->input_views[i]->width,
+                           s->input_views[i]->height);
         }
     }
 }
@@ -263,15 +259,10 @@ static void vertical_frame_pack(AVFilterLink *outlink,
     int i;
 
     for (i = 0; i < 2; i++) {
-        const uint8_t *src[4];
         uint8_t *dst[4];
         int linesizes[4];
         int sub_h = s->input_views[i]->height >> s->pix_desc->log2_chroma_h;
 
-        src[0] = s->input_views[i]->data[0];
-        src[1] = s->input_views[i]->data[1];
-        src[2] = s->input_views[i]->data[2];
-
         dst[0] = out->data[0] + i * out->linesize[0] *
                  (interleaved + s->input_views[i]->height * (1 - interleaved));
         dst[1] = out->data[1] + i * out->linesize[1] *
@@ -286,10 +277,11 @@ static void vertical_frame_pack(AVFilterLink *outlink,
         linesizes[2] = out->linesize[2] +
                        interleaved * out->linesize[2];
 
-        av_image_copy(dst, linesizes, src, s->input_views[i]->linesize,
-                      s->input_views[i]->format,
-                      s->input_views[i]->width,
-                      s->input_views[i]->height);
+        av_image_copy2(dst, linesizes,
+                       s->input_views[i]->data, s->input_views[i]->linesize,
+                       s->input_views[i]->format,
+                       s->input_views[i]->width,
+                       s->input_views[i]->height);
     }
 }
 

libavfilter/vf_pullup.c

@@ -666,9 +666,9 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
         goto end;
     }
 
-    av_image_copy(b->planes, s->planewidth,
-                  (const uint8_t**)in->data, in->linesize,
-                  inlink->format, inlink->w, inlink->h);
+    av_image_copy2(b->planes, s->planewidth,
+                   in->data, in->linesize,
+                   inlink->format, inlink->w, inlink->h);
 
     p = (in->flags & AV_FRAME_FLAG_INTERLACED) ?
         !(in->flags & AV_FRAME_FLAG_TOP_FIELD_FIRST) : 0;
@@ -714,9 +714,9 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     }
     av_frame_copy_props(out, in);
 
-    av_image_copy(out->data, out->linesize,
-                  (const uint8_t**)f->buffer->planes, s->planewidth,
-                  inlink->format, inlink->w, inlink->h);
+    av_image_copy2(out->data, out->linesize,
+                   f->buffer->planes, s->planewidth,
+                   inlink->format, inlink->w, inlink->h);
 
     ret = ff_filter_frame(outlink, out);
     pullup_release_frame(f);

libavfilter/yadif_common.c

@@ -89,9 +89,9 @@ static void fixstride(AVFilterLink *link, AVFrame *f)
     if(!dst)
         return;
     av_frame_copy_props(dst, f);
-    av_image_copy(dst->data, dst->linesize,
-                  (const uint8_t **)f->data, f->linesize,
-                  dst->format, dst->width, dst->height);
+    av_image_copy2(dst->data, dst->linesize,
+                   f->data, f->linesize,
+                   dst->format, dst->width, dst->height);
     av_frame_unref(f);
     av_frame_move_ref(f, dst);
     av_frame_free(&dst);

libavutil/frame.c

@@ -833,7 +833,6 @@ AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
 
 static int frame_copy_video(AVFrame *dst, const AVFrame *src)
 {
-    const uint8_t *src_data[4];
     int planes;
 
     if (dst->width  < src->width ||
@@ -848,10 +847,9 @@ static int frame_copy_video(AVFrame *dst, const AVFrame *src)
         if (!dst->data[i] || !src->data[i])
             return AVERROR(EINVAL);
 
-    memcpy(src_data, src->data, sizeof(src_data));
-    av_image_copy(dst->data, dst->linesize,
-                  src_data, src->linesize,
-                  dst->format, src->width, src->height);
+    av_image_copy2(dst->data, dst->linesize,
+                   src->data, src->linesize,
+                   dst->format, src->width, src->height);
 
     return 0;
 }

libavutil/hwcontext_d3d11va.c

@@ -452,8 +452,8 @@ static int d3d11va_transfer_data(AVHWFramesContext *ctx, AVFrame *dst,
 
         fill_texture_ptrs(map_data, map_linesize, ctx, &desc, &map);
 
-        av_image_copy(dst->data, dst->linesize, (const uint8_t **)map_data, map_linesize,
-                      ctx->sw_format, w, h);
+        av_image_copy2(dst->data, dst->linesize, map_data, map_linesize,
+                       ctx->sw_format, w, h);
 
         ID3D11DeviceContext_Unmap(device_hwctx->device_context, staging, 0);
     } else {
@@ -464,8 +464,8 @@ static int d3d11va_transfer_data(AVHWFramesContext *ctx, AVFrame *dst,
 
         fill_texture_ptrs(map_data, map_linesize, ctx, &desc, &map);
 
-        av_image_copy(map_data, map_linesize, (const uint8_t **)src->data, src->linesize,
-                      ctx->sw_format, w, h);
+        av_image_copy2(map_data, map_linesize, src->data, src->linesize,
+                       ctx->sw_format, w, h);
 
         ID3D11DeviceContext_Unmap(device_hwctx->device_context, staging, 0);
 

libavutil/hwcontext_dxva2.c

@@ -356,8 +356,8 @@ static int dxva2_transfer_data_to(AVHWFramesContext *ctx, AVFrame *dst,
     if (ret < 0)
         goto fail;
 
-    av_image_copy(map->data, map->linesize, (const uint8_t **)src->data, src->linesize,
-                  ctx->sw_format, src->width, src->height);
+    av_image_copy2(map->data, map->linesize, src->data, src->linesize,
+                   ctx->sw_format, src->width, src->height);
 
 fail:
     av_frame_free(&map);

libavutil/imgutils.h

@@ -174,6 +174,22 @@ void av_image_copy(uint8_t * const dst_data[4], const int dst_linesizes[4],
                    const uint8_t * const src_data[4], const int src_linesizes[4],
                    enum AVPixelFormat pix_fmt, int width, int height);
 
+/**
+ * Wrapper around av_image_copy() to workaround the limitation
+ * that the conversion from uint8_t * const * to const uint8_t * const *
+ * is not performed automatically in C.
+ * @see av_image_copy()
+ */
+static inline
+void av_image_copy2(uint8_t * const dst_data[4], const int dst_linesizes[4],
+                    uint8_t * const src_data[4], const int src_linesizes[4],
+                    enum AVPixelFormat pix_fmt, int width, int height)
+{
+    av_image_copy(dst_data, dst_linesizes,
+                  (const uint8_t * const *)src_data, src_linesizes,
+                  pix_fmt, width, height);
+}
+
 /**
  * Copy image data located in uncacheable (e.g. GPU mapped) memory. Where
  * available, this function will use special functionality for reading from such

libavutil/version.h

@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  58
-#define LIBAVUTIL_VERSION_MINOR  23
+#define LIBAVUTIL_VERSION_MINOR  24
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \