avcodec/mediacodecdec: add debug logging around hw buffer lifecycle

Some Android devices are very finicky about how quicky output buffers
are returned back to the decoder, especially when they are associated
with a Surface.

This commit adds a new counter that keeps track of exactly how many hw
output buffers are being retained by the user, along with DEBUG level
logging that makes it easy to track the lifecycle of these buffers.

Signed-off-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Matthieu Bouron <matthieu.bouron@gmail.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/libavcodec/mediacodecdec_common.c b/libavcodec/mediacodecdec_common.c
index 5064809..2697af3 100644
--- a/libavcodec/mediacodecdec_common.c
+++ b/libavcodec/mediacodecdec_common.c
@@ -179,6 +179,10 @@ static void mediacodec_buffer_release(void *opaque, uint8_t *data)
     int released = atomic_load(&buffer->released);
 
     if (!released && (ctx->delay_flush || buffer->serial == atomic_load(&ctx->serial))) {
+        atomic_fetch_sub(&ctx->hw_buffer_count, 1);
+        av_log(ctx->avctx, AV_LOG_DEBUG,
+               "Releasing output buffer %zd (%p) ts=%"PRId64" on free() [%d pending]\n",
+               buffer->index, buffer, buffer->pts, atomic_load(&ctx->hw_buffer_count));
         ff_AMediaCodec_releaseOutputBuffer(ctx->codec, buffer->index, 0);
     }
 
@@ -246,6 +250,11 @@ FF_ENABLE_DEPRECATION_WARNINGS
 
     frame->data[3] = (uint8_t *)buffer;
 
+    atomic_fetch_add(&s->hw_buffer_count, 1);
+    av_log(avctx, AV_LOG_DEBUG,
+            "Wrapping output buffer %zd (%p) ts=%"PRId64" [%d pending]\n",
+            buffer->index, buffer, buffer->pts, atomic_load(&s->hw_buffer_count));
+
     return 0;
 fail:
     av_freep(buffer);
@@ -429,6 +438,7 @@ static int mediacodec_dec_flush_codec(AVCodecContext *avctx, MediaCodecDecContex
     s->flushing = 0;
     s->eos = 0;
     atomic_fetch_add(&s->serial, 1);
+    atomic_init(&s->hw_buffer_count, 0);
 
     status = ff_AMediaCodec_flush(codec);
     if (status < 0) {
@@ -454,6 +464,7 @@ int ff_mediacodec_dec_init(AVCodecContext *avctx, MediaCodecDecContext *s,
 
     s->avctx = avctx;
     atomic_init(&s->refcount, 1);
+    atomic_init(&s->hw_buffer_count, 0);
     atomic_init(&s->serial, 1);
 
     pix_fmt = ff_get_format(avctx, pix_fmts);