diff --git a/ffmpeg.c b/ffmpeg.c
index dc53f34c34..544927956f 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -592,10 +592,12 @@ static void do_audio_out(AVFormatContext *s,
 
         frame_bytes = enc->frame_size * 2 * enc->channels;
 
-        while (av_fifo_read(&ost->fifo, audio_buf, frame_bytes) == 0) {
+        while (av_fifo_size(&ost->fifo) >= frame_bytes) {
             AVPacket pkt;
             av_init_packet(&pkt);
 
+            av_fifo_read(&ost->fifo, audio_buf, frame_bytes);
+
             //FIXME pass ost->sync_opts as AVFrame.pts in avcodec_encode_audio()
 
             ret = avcodec_encode_audio(enc, audio_out, audio_out_size,
@@ -1385,9 +1387,8 @@ static int output_packet(AVInputStream *ist, int ist_index,
                             if(fifo_bytes > 0 && enc->codec->capabilities & CODEC_CAP_SMALL_LAST_FRAME) {
                                 int fs_tmp = enc->frame_size;
                                 enc->frame_size = fifo_bytes / (2 * enc->channels);
-                                if(av_fifo_read(&ost->fifo, (uint8_t *)samples, fifo_bytes) == 0) {
+                                av_fifo_read(&ost->fifo, (uint8_t *)samples, fifo_bytes);
                                     ret = avcodec_encode_audio(enc, bit_buffer, bit_buffer_size, samples);
-                                }
                                 enc->frame_size = fs_tmp;
                             }
                             if(ret <= 0) {
diff --git a/libavformat/mpegenc.c b/libavformat/mpegenc.c
index 05c72cd1e7..c96ffd1684 100644
--- a/libavformat/mpegenc.c
+++ b/libavformat/mpegenc.c
@@ -913,8 +913,8 @@ static int flush_packet(AVFormatContext *ctx, int stream_index,
         }
 
         /* output data */
-        if(av_fifo_generic_read(&stream->fifo, payload_size - stuffing_size, &put_buffer, ctx->pb) < 0)
-            return -1;
+        assert(payload_size - stuffing_size <= av_fifo_size(&stream->fifo));
+        av_fifo_generic_read(&stream->fifo, payload_size - stuffing_size, &put_buffer, ctx->pb);
         stream->bytes_to_iframe -= payload_size - stuffing_size;
     }else{
         payload_size=
diff --git a/libavutil/fifo.c b/libavutil/fifo.c
index 19ec13e63d..f2ace514bd 100644
--- a/libavutil/fifo.c
+++ b/libavutil/fifo.c
@@ -45,9 +45,6 @@ int av_fifo_size(AVFifoBuffer *f)
     return size;
 }
 
-/**
- * Get data from the fifo (returns -1 if not enough data).
- */
 int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
 {
     return av_fifo_generic_read(f, buf_size, NULL, buf);
@@ -97,13 +94,8 @@ int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void
 }
 
 
-/** get data from the fifo (return -1 if not enough data) */
 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
 {
-    int size = av_fifo_size(f);
-
-    if (size < buf_size)
-        return -1;
     do {
         int len = FFMIN(f->end - f->rptr, buf_size);
         if(func) func(dest, f->rptr, len);