avcodec/thread: Don't use ThreadFrame when unnecessary

The majority of frame-threaded decoders (mainly the intra-only)
need exactly one part of ThreadFrame: The AVFrame. They don't
need the owners nor the progress, yet they had to use it because
ff_thread_(get|release)_buffer() requires it.

This commit changes this and makes these functions work with ordinary
AVFrames; the decoders that need the extra fields for progress
use ff_thread_(get|release)_ext_buffer() which work exactly
as ff_thread_(get|release)_buffer() used to do.

This also avoids some unnecessary allocations of progress AVBuffers,
namely for H.264 and HEVC film grain frames: These frames are not
used for synchronization and therefore don't need a ThreadFrame.

Also move the ThreadFrame structure as well as ff_thread_ref_frame()
to threadframe.h, the header for frame-threaded decoders with
inter-frame dependencies.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 5 insertions, 6 deletions

diff --git a/libavcodec/mdec.c b/libavcodec/mdec.c
index 007e7fada8..9f61256bc4 100644
--- a/libavcodec/mdec.c
+++ b/libavcodec/mdec.c
@@ -42,7 +42,6 @@ typedef struct MDECContext {
     BlockDSPContext bdsp;
     BswapDSPContext bbdsp;
     IDCTDSPContext idsp;
-    ThreadFrame frame;
     GetBitContext gb;
     ScanTable scantable;
     int version;
@@ -174,13 +173,13 @@ static int decode_frame(AVCodecContext *avctx,
     MDECContext * const a = avctx->priv_data;
     const uint8_t *buf    = avpkt->data;
     int buf_size          = avpkt->size;
-    ThreadFrame frame     = { .f = data };
+    AVFrame *const frame  = data;
     int ret;
 
-    if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
+    if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
         return ret;
-    frame.f->pict_type = AV_PICTURE_TYPE_I;
-    frame.f->key_frame = 1;
+    frame->pict_type = AV_PICTURE_TYPE_I;
+    frame->key_frame = 1;
 
     av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);
     if (!a->bitstream_buffer)
@@ -202,7 +201,7 @@ static int decode_frame(AVCodecContext *avctx,
             if ((ret = decode_mb(a, a->block)) < 0)
                 return ret;
 
-            idct_put(a, frame.f, a->mb_x, a->mb_y);
+            idct_put(a, frame, a->mb_x, a->mb_y);
         }
     }