diff --git a/libavformat/adtsenc.c b/libavformat/adtsenc.c
index 0c9194449e..e7c9ca6ce1 100644
--- a/libavformat/adtsenc.c
+++ b/libavformat/adtsenc.c
@@ -158,7 +158,6 @@ static int adts_write_packet(AVFormatContext *s, AVPacket *pkt)
         }
     }
     avio_write(pb, pkt->data, pkt->size);
-    avio_flush(pb);
 
     return 0;
 }
diff --git a/libavformat/amr.c b/libavformat/amr.c
index ba91d7c139..3b1a468e34 100644
--- a/libavformat/amr.c
+++ b/libavformat/amr.c
@@ -55,7 +55,6 @@ static int amr_write_header(AVFormatContext *s)
 static int amr_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     avio_write(s->pb, pkt->data, pkt->size);
-    avio_flush(s->pb);
     return 0;
 }
 #endif /* CONFIG_AMR_MUXER */
diff --git a/libavformat/assenc.c b/libavformat/assenc.c
index 5bf2e20134..751485dfb5 100644
--- a/libavformat/assenc.c
+++ b/libavformat/assenc.c
@@ -58,9 +58,6 @@ static int write_header(AVFormatContext *s)
 static int write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     avio_write(s->pb, pkt->data, pkt->size);
-
-    avio_flush(s->pb);
-
     return 0;
 }
 
diff --git a/libavformat/avienc.c b/libavformat/avienc.c
index 9d1f5102a1..751687e658 100644
--- a/libavformat/avienc.c
+++ b/libavformat/avienc.c
@@ -558,7 +558,6 @@ static int avi_write_packet(AVFormatContext *s, AVPacket *pkt)
     if (size & 1)
         avio_w8(pb, 0);
 
-    avio_flush(pb);
     return 0;
 }
 
diff --git a/libavformat/daud.c b/libavformat/daud.c
index 3ceb958d61..bb7ab7fbcd 100644
--- a/libavformat/daud.c
+++ b/libavformat/daud.c
@@ -68,7 +68,6 @@ static int daud_write_packet(struct AVFormatContext *s, AVPacket *pkt)
     avio_wb16(s->pb, pkt->size);
     avio_wb16(s->pb, 0x8010); // unknown
     avio_write(s->pb, pkt->data, pkt->size);
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/dvenc.c b/libavformat/dvenc.c
index a991cc6b0c..93ae0b56dc 100644
--- a/libavformat/dvenc.c
+++ b/libavformat/dvenc.c
@@ -388,7 +388,6 @@ static int dv_write_packet(struct AVFormatContext *s, AVPacket *pkt)
                               pkt->data, pkt->size, &frame);
     if (fsize > 0) {
         avio_write(s->pb, frame, fsize);
-        avio_flush(s->pb);
     }
     return 0;
 }
diff --git a/libavformat/flacenc.c b/libavformat/flacenc.c
index b770623b3c..1e4042e070 100644
--- a/libavformat/flacenc.c
+++ b/libavformat/flacenc.c
@@ -113,7 +113,6 @@ static int flac_write_trailer(struct AVFormatContext *s)
 static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
 {
     avio_write(s->pb, pkt->data, pkt->size);
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index 37f37773a0..bcb135dad3 100644
--- a/libavformat/flvenc.c
+++ b/libavformat/flvenc.c
@@ -545,7 +545,6 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
                               pkt->pts + flv->delay + pkt->duration);
     }
 
-    avio_flush(pb);
     av_free(data);
 
     return pb->error;
diff --git a/libavformat/framecrcenc.c b/libavformat/framecrcenc.c
index fed0cca430..dd55c129f0 100644
--- a/libavformat/framecrcenc.c
+++ b/libavformat/framecrcenc.c
@@ -31,7 +31,6 @@ static int framecrc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
     snprintf(buf, sizeof(buf), "%d, %10"PRId64", %10"PRId64", %8d, %8d, 0x%08x\n",
              pkt->stream_index, pkt->dts, pkt->pts, pkt->duration, pkt->size, crc);
     avio_write(s->pb, buf, strlen(buf));
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/gif.c b/libavformat/gif.c
index 2b1e93ad9f..085c2e03fc 100644
--- a/libavformat/gif.c
+++ b/libavformat/gif.c
@@ -329,7 +329,6 @@ static int gif_write_video(AVFormatContext *s, AVCodecContext *enc,
     gif_image_write_image(pb, 0, 0, enc->width, enc->height,
                           buf, enc->width * 3, AV_PIX_FMT_RGB24);
 
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/gxfenc.c b/libavformat/gxfenc.c
index 74df237e61..fea1d5d818 100644
--- a/libavformat/gxfenc.c
+++ b/libavformat/gxfenc.c
@@ -896,8 +896,6 @@ static int gxf_write_packet(AVFormatContext *s, AVPacket *pkt)
         gxf->packet_count = 0;
     }
 
-    avio_flush(pb);
-
     return 0;
 }
 
diff --git a/libavformat/ilbc.c b/libavformat/ilbc.c
index c01eb6f796..e44af487b2 100644
--- a/libavformat/ilbc.c
+++ b/libavformat/ilbc.c
@@ -56,7 +56,6 @@ static int ilbc_write_header(AVFormatContext *s)
 static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     avio_write(s->pb, pkt->data, pkt->size);
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
index e0455970e5..3cd16166c7 100644
--- a/libavformat/ivfenc.c
+++ b/libavformat/ivfenc.c
@@ -53,7 +53,6 @@ static int ivf_write_packet(AVFormatContext *s, AVPacket *pkt)
     avio_wl32(pb, pkt->size);
     avio_wl64(pb, pkt->pts);
     avio_write(pb, pkt->data, pkt->size);
-    avio_flush(pb);
 
     return 0;
 }
diff --git a/libavformat/mpjpeg.c b/libavformat/mpjpeg.c
index 6c8bd0ce17..2114189244 100644
--- a/libavformat/mpjpeg.c
+++ b/libavformat/mpjpeg.c
@@ -44,7 +44,6 @@ static int mpjpeg_write_packet(AVFormatContext *s, AVPacket *pkt)
 
     snprintf(buf1, sizeof(buf1), "\n--%s\n", BOUNDARY_TAG);
     avio_write(s->pb, buf1, strlen(buf1));
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/rawenc.c b/libavformat/rawenc.c
index 171c603549..852a27d6e4 100644
--- a/libavformat/rawenc.c
+++ b/libavformat/rawenc.c
@@ -26,7 +26,6 @@
 int ff_raw_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     avio_write(s->pb, pkt->data, pkt->size);
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/rmenc.c b/libavformat/rmenc.c
index ed1ba7c75b..fba8feb802 100644
--- a/libavformat/rmenc.c
+++ b/libavformat/rmenc.c
@@ -369,7 +369,6 @@ static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int
     } else {
         avio_write(pb, buf, size);
     }
-    avio_flush(pb);
     stream->nb_frames++;
     av_free(buf1);
     return 0;
@@ -414,7 +413,6 @@ static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int
     avio_w8(pb, stream->nb_frames & 0xff);
 
     avio_write(pb, buf, size);
-    avio_flush(pb);
 
     stream->nb_frames++;
     return 0;
diff --git a/libavformat/smjpegenc.c b/libavformat/smjpegenc.c
index 5c64e844ad..551af8911d 100644
--- a/libavformat/smjpegenc.c
+++ b/libavformat/smjpegenc.c
@@ -109,7 +109,6 @@ static int smjpeg_write_packet(AVFormatContext *s, AVPacket *pkt)
     avio_wb32(pb, pkt->pts);
     avio_wb32(pb, pkt->size);
     avio_write(pb, pkt->data, pkt->size);
-    avio_flush(pb);
 
     smc->duration = FFMAX(smc->duration, pkt->pts + pkt->duration);
     return 0;
diff --git a/libavformat/spdifenc.c b/libavformat/spdifenc.c
index 1f37340a8b..c350f7251c 100644
--- a/libavformat/spdifenc.c
+++ b/libavformat/spdifenc.c
@@ -538,7 +538,6 @@ static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
     av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
            ctx->data_type, ctx->out_bytes, ctx->pkt_offset);
 
-    avio_flush(s->pb);
     return 0;
 }
 
diff --git a/libavformat/swfenc.c b/libavformat/swfenc.c
index 93487cc21a..be2e5cd7d3 100644
--- a/libavformat/swfenc.c
+++ b/libavformat/swfenc.c
@@ -436,8 +436,6 @@ static int swf_write_video(AVFormatContext *s,
     put_swf_tag(s, TAG_SHOWFRAME);
     put_swf_end_tag(s);
 
-    avio_flush(s->pb);
-
     return 0;
 }
 
diff --git a/libavformat/vc1testenc.c b/libavformat/vc1testenc.c
index abe8c6b231..9d55fee46d 100644
--- a/libavformat/vc1testenc.c
+++ b/libavformat/vc1testenc.c
@@ -63,7 +63,6 @@ static int vc1test_write_packet(AVFormatContext *s, AVPacket *pkt)
     avio_wl32(pb, pkt->size | ((pkt->flags & AV_PKT_FLAG_KEY) ? 0x80000000 : 0));
     avio_wl32(pb, pkt->pts);
     avio_write(pb, pkt->data, pkt->size);
-    avio_flush(pb);
     ctx->frames++;
 
     return 0;
diff --git a/libavformat/wvenc.c b/libavformat/wvenc.c
index 0ce08e884c..2e150e1a7a 100644
--- a/libavformat/wvenc.c
+++ b/libavformat/wvenc.c
@@ -51,7 +51,6 @@ static int wv_write_packet(AVFormatContext *ctx, AVPacket *pkt)
     s->samples += header.samples;
 
     avio_write(ctx->pb, pkt->data, pkt->size);
-    avio_flush(ctx->pb);
 
     return 0;
 }
diff --git a/libavformat/yuv4mpeg.c b/libavformat/yuv4mpeg.c
index c38d641e06..cc2755f4b6 100644
--- a/libavformat/yuv4mpeg.c
+++ b/libavformat/yuv4mpeg.c
@@ -147,7 +147,6 @@ static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)
             ptr2 += picture->linesize[2];
         }
     }
-    avio_flush(pb);
     return 0;
 }