[FFmpeg-devel] [PATCH 7/9] lavc/decode: track whether the caller started draining with a separate flag

Anton Khirnov anton at khirnov.net
Tue Jun 20 17:16:06 EEST 2023


Decoding pipeline has multiple stages, some of which may have their own
delay (e.g. bitstream filters). The code currently uses
AVCodecInternal.draining to track all of them, but they do not have to
all be in sync.
---
 libavcodec/decode.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index c070148b58..c61ce74fb8 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -53,6 +53,11 @@
 struct DecodeContext {
     /* to prevent infinite loop on errors when draining */
     int nb_draining_errors;
+
+    /**
+     * The caller has submitted a NULL packet on input.
+     */
+    int draining_started;
 };
 
 static int apply_param_change(AVCodecContext *avctx, const AVPacket *avpkt)
@@ -624,7 +629,7 @@ int attribute_align_arg avcodec_send_packet(AVCodecContext *avctx, const AVPacke
     if (!avcodec_is_open(avctx) || !av_codec_is_decoder(avctx->codec))
         return AVERROR(EINVAL);
 
-    if (avctx->internal->draining)
+    if (avci->d->draining_started)
         return AVERROR_EOF;
 
     if (avpkt && !avpkt->size && avpkt->data)
@@ -635,7 +640,8 @@ int attribute_align_arg avcodec_send_packet(AVCodecContext *avctx, const AVPacke
         ret = av_packet_ref(avci->buffer_pkt, avpkt);
         if (ret < 0)
             return ret;
-    }
+    } else
+        avci->d->draining_started = 1;
 
     ret = av_bsf_send_packet(avci->bsf, avci->buffer_pkt);
     if (ret < 0) {
@@ -1758,6 +1764,7 @@ void ff_decode_flush_buffers(AVCodecContext *avctx)
     av_bsf_flush(avci->bsf);
 
     avci->d->nb_draining_errors = 0;
+    avci->d->draining_started   = 0;
 }
 
 AVCodecInternal *ff_decode_internal_alloc(void)
-- 
2.40.1



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