[FFmpeg-devel] [PATCH 13/14] mmal: add option copy_frame to support retrieving sw frames w/o copy

[wbsecg1 at gmail.com]

From: wang-bin <wbsecg1 at gmail.com>

mmal buffer->data is already in host memory. AFAIK decoders implemented in omx must
be configured to output frames to either memory or something directly used by renderer,
for example mediacodec surface, mmal buffer and omxil eglimage.
test result: big buck bunny 1080p fps increases from about 100 to 110 if copy_frame is
turned off
---
 libavcodec/mmaldec.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/libavcodec/mmaldec.c b/libavcodec/mmaldec.c
index c1cfb09283..9cd6c6558f 100644
--- a/libavcodec/mmaldec.c
+++ b/libavcodec/mmaldec.c
@@ -69,6 +69,7 @@ typedef struct MMALDecodeContext {
     AVClass *av_class;
     int extra_buffers;
     int extra_decoder_buffers;
+    int copy_frame;
 
     MMAL_COMPONENT_T *decoder;
     MMAL_QUEUE_T *queue_decoded_frames;
@@ -139,7 +140,6 @@ static int ffmmal_set_ref(AVFrame *frame, FFPoolRef *pool,
     atomic_fetch_add_explicit(&ref->pool->refcount, 1, memory_order_relaxed);
     mmal_buffer_header_acquire(buffer);
 
-    frame->format = AV_PIX_FMT_MMAL;
     frame->data[3] = (uint8_t *)ref->buffer;
     return 0;
 }
@@ -650,20 +650,34 @@ static int ffmal_copy_frame(AVCodecContext *avctx,  AVFrame *frame,
 
         if ((ret = ffmmal_set_ref(frame, ctx->pool_out, buffer)) < 0)
             goto done;
+        frame->format = AV_PIX_FMT_MMAL;
     } else {
         int w = FFALIGN(avctx->width, 32);
         int h = FFALIGN(avctx->height, 16);
         uint8_t *src[4];
         int linesize[4];
 
-        if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
-            goto done;
+        if (ctx->copy_frame) {
+            if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+                goto done;
 
-        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, src, linesize,
-                      avctx->pix_fmt, avctx->width, avctx->height);
+            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, src, linesize,
+                        avctx->pix_fmt, avctx->width, avctx->height);
+        } else {
+            if ((ret = ff_decode_frame_props(avctx, frame)) < 0)
+                goto done;
+            /* buffer->type->video.offset/pitch[i]; is always 0 */
+            av_image_fill_arrays(src, linesize,
+                                buffer->data + buffer->type->video.offset[0],
+                                avctx->pix_fmt, w, h, 1);
+            if ((ret = ffmmal_set_ref(frame, ctx->pool_out, buffer)) < 0)
+                goto done;
+            memcpy(frame->data, src, sizeof(src));
+            memcpy(frame->linesize, linesize, sizeof(linesize));
+        }
     }
 
     frame->pts = buffer->pts == MMAL_TIME_UNKNOWN ? AV_NOPTS_VALUE : buffer->pts;
@@ -842,6 +856,7 @@ AVHWAccel ff_wmv3_mmal_hwaccel = {
 static const AVOption options[]={
     {"extra_buffers", "extra buffers", offsetof(MMALDecodeContext, extra_buffers), AV_OPT_TYPE_INT, {.i64 = 10}, 0, 256, 0},
     {"extra_decoder_buffers", "extra MMAL internal buffered frames", offsetof(MMALDecodeContext, extra_decoder_buffers), AV_OPT_TYPE_INT, {.i64 = 10}, 0, 256, 0},
+    {"copy_frame", "copy deocded data to avframe", offsetof(MMALDecodeContext, copy_frame), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 256, 0},
     {NULL}
 };
 
-- 
2.15.1