mimic: drop AVPicture usage

Work on the AVFrame references directly.

Instead of setting up a flipped/swapped "view" on the pictures,
flip/swap them when returning decoded frames to the API user.

libavcodec/mimic.c

@@ -48,7 +48,6 @@ typedef struct MimicContext {
     int             prev_index;
 
     ThreadFrame     frames     [16];
-    AVPicture       flipped_ptrs[16];
 
     DECLARE_ALIGNED(16, int16_t, dct_block)[64];
 
@@ -177,8 +176,6 @@ static int mimic_decode_update_thread_context(AVCodecContext *avctx, const AVCod
     dst->cur_index  = src->next_cur_index;
     dst->prev_index = src->next_prev_index;
 
-    memcpy(dst->flipped_ptrs, src->flipped_ptrs, sizeof(src->flipped_ptrs));
-
     for (i = 0; i < FF_ARRAY_ELEMS(dst->frames); i++) {
         ff_thread_release_buffer(avctx, &dst->frames[i]);
         if (src->frames[i].f->data[0]) {
@@ -281,9 +278,9 @@ static int decode(MimicContext *ctx, int quality, int num_coeffs,
         const int is_chroma = !!plane;
         const int qscale    = av_clip(10000 - quality, is_chroma ? 1000 : 2000,
                                       10000) << 2;
-        const int stride    = ctx->flipped_ptrs[ctx->cur_index ].linesize[plane];
-        const uint8_t *src  = ctx->flipped_ptrs[ctx->prev_index].data[plane];
-        uint8_t       *dst  = ctx->flipped_ptrs[ctx->cur_index ].data[plane];
+        const int stride    = ctx->frames[ctx->cur_index ].f->linesize[plane];
+        const uint8_t *src  = ctx->frames[ctx->prev_index].f->data[plane];
+        uint8_t       *dst  = ctx->frames[ctx->cur_index ].f->data[plane];
 
         for (y = 0; y < ctx->num_vblocks[plane]; y++) {
             for (x = 0; x < ctx->num_hblocks[plane]; x++) {
@@ -306,13 +303,13 @@ static int decode(MimicContext *ctx, int quality, int num_coeffs,
                     } else {
                         unsigned int backref = get_bits(&ctx->gb, 4);
                         int index            = (ctx->cur_index + backref) & 15;
-                        uint8_t *p           = ctx->flipped_ptrs[index].data[0];
+                        uint8_t *p           = ctx->frames[index].f->data[0];
 
                         if (index != ctx->cur_index && p) {
                             ff_thread_await_progress(&ctx->frames[index],
                                                      cur_row, 0);
                             p += src -
-                                 ctx->flipped_ptrs[ctx->prev_index].data[plane];
+                                 ctx->frames[ctx->prev_index].f->data[plane];
                             ctx->hdsp.put_pixels_tab[1][0](dst, p, stride, 8);
                         } else {
                             av_log(ctx->avctx, AV_LOG_ERROR,
@@ -339,17 +336,18 @@ static int decode(MimicContext *ctx, int quality, int num_coeffs,
 }
 
 /**
- * Flip the buffer upside-down and put it in the YVU order to match the
+ * Flip the buffer upside-down and put it in the YVU order to revert the
  * way Mimic encodes frames.
  */
-static void prepare_avpic(MimicContext *ctx, AVPicture *dst, AVFrame *src)
+static void flip_swap_frame(AVFrame *f)
 {
     int i;
-    dst->data[0] = src->data[0] + ( ctx->avctx->height       - 1) * src->linesize[0];
-    dst->data[1] = src->data[2] + ((ctx->avctx->height >> 1) - 1) * src->linesize[2];
-    dst->data[2] = src->data[1] + ((ctx->avctx->height >> 1) - 1) * src->linesize[1];
+    uint8_t *data_1 = f->data[1];
+    f->data[0] = f->data[0] + ( f->height       - 1) * f->linesize[0];
+    f->data[1] = f->data[2] + ((f->height >> 1) - 1) * f->linesize[2];
+    f->data[2] = data_1     + ((f->height >> 1) - 1) * f->linesize[1];
     for (i = 0; i < 3; i++)
-        dst->linesize[i] = -src->linesize[i];
+        f->linesize[i] *= -1;
 }
 
 static int mimic_decode_frame(AVCodecContext *avctx, void *data,
@@ -419,9 +417,6 @@ static int mimic_decode_frame(AVCodecContext *avctx, void *data,
     ctx->next_prev_index = ctx->cur_index;
     ctx->next_cur_index  = (ctx->cur_index - 1) & 15;
 
-    prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index],
-                  ctx->frames[ctx->cur_index].f);
-
     ff_thread_finish_setup(avctx);
 
     av_fast_padded_malloc(&ctx->swap_buf, &ctx->swap_buf_size, swap_buf_size);
@@ -446,6 +441,8 @@ static int mimic_decode_frame(AVCodecContext *avctx, void *data,
         return res;
     *got_frame      = 1;
 
+    flip_swap_frame(data);
+
     ctx->prev_index = ctx->next_prev_index;
     ctx->cur_index  = ctx->next_cur_index;