[FFmpeg-devel] [PATCH v2] avcodec/nvenc: fix flushing for encoder-reuse

Jai Luthra me at jailuthra.in
Fri Jul 16 19:09:42 EEST 2021


Recent encode API restructure (827d6fe73d) removed some state - which broke
the API for flushing without closing the encoder.

This functionality was originally added in 3ea7057677 and is useful for
segmented video, where we don't want to do expensive re-init of HW sessions
for every segment.
---
v2: Forgot to rebase off master in v1

 libavcodec/nvenc.c | 16 +++++++++++-----
 libavcodec/nvenc.h |  2 ++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/libavcodec/nvenc.c b/libavcodec/nvenc.c
index ee046b9cef..ee0beb4795 100644
--- a/libavcodec/nvenc.c
+++ b/libavcodec/nvenc.c
@@ -2281,6 +2281,11 @@ static int nvenc_send_frame(AVCodecContext *avctx, const AVFrame *frame)
         return AVERROR(EINVAL);
 
     if (frame && frame->buf[0]) {
+        if (ctx->encoder_flushing) {
+            ctx->encoder_flushing = 0;
+            av_fifo_reset(ctx->timestamp_list);
+        }
+
         in_surf = get_free_frame(ctx);
         if (!in_surf)
             return AVERROR(EAGAIN);
@@ -2335,6 +2340,7 @@ static int nvenc_send_frame(AVCodecContext *avctx, const AVFrame *frame)
         nvenc_codec_specific_pic_params(avctx, &pic_params, ctx->sei_data, sei_count);
     } else {
         pic_params.encodePicFlags = NV_ENC_PIC_FLAG_EOS;
+        ctx->encoder_flushing = 1;
     }
 
     res = nvenc_push_context(avctx);
@@ -2384,8 +2390,11 @@ int ff_nvenc_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
 
     if (!frame->buf[0]) {
         res = ff_encode_get_frame(avctx, frame);
-        if (res < 0 && res != AVERROR_EOF)
+        if (res == AVERROR_EOF || (ctx->encoder_flushing && res == AVERROR(EAGAIN))) {
+            // flushing mode, continue to send packets
+        } else if (res < 0) {
             return res;
+        }
     }
 
     res = nvenc_send_frame(avctx, frame);
@@ -2395,7 +2404,7 @@ int ff_nvenc_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
     } else
         av_frame_unref(frame);
 
-    if (output_ready(avctx, avctx->internal->draining)) {
+    if (output_ready(avctx, ctx->encoder_flushing)) {
         av_fifo_generic_read(ctx->output_surface_ready_queue, &tmp_out_surf, sizeof(tmp_out_surf), NULL);
 
         res = nvenc_push_context(avctx);
@@ -2423,8 +2432,5 @@ int ff_nvenc_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
 
 av_cold void ff_nvenc_encode_flush(AVCodecContext *avctx)
 {
-    NvencContext *ctx = avctx->priv_data;
-
     nvenc_send_frame(avctx, NULL);
-    av_fifo_reset(ctx->timestamp_list);
 }
diff --git a/libavcodec/nvenc.h b/libavcodec/nvenc.h
index 85d3a33601..6af3aaf0ce 100644
--- a/libavcodec/nvenc.h
+++ b/libavcodec/nvenc.h
@@ -169,6 +169,8 @@ typedef struct NvencContext
     NV_ENC_SEI_PAYLOAD *sei_data;
     int sei_data_size;
 
+    int encoder_flushing;
+
     struct {
         void *ptr;
         int ptr_index;
-- 
2.32.0



More information about the ffmpeg-devel mailing list