ffplay: remove redundant silence buffer

Signed-off-by: Lukasz Marek <lukasz.m.luki2@gmail.com>

ffplay.c

@@ -243,7 +243,6 @@ typedef struct VideoState {
     AVStream *audio_st;
     PacketQueue audioq;
     int audio_hw_buf_size;
-    uint8_t silence_buf[SDL_AUDIO_MIN_BUFFER_SIZE];
     uint8_t *audio_buf;
     uint8_t *audio_buf1;
     unsigned int audio_buf_size; /* in bytes */
@@ -2532,7 +2531,7 @@ static int audio_decode_frame(VideoState *is)
 static void sdl_audio_callback(void *opaque, Uint8 *stream, int len)
 {
     VideoState *is = opaque;
-    int audio_size, len1;
+    int audio_size, len1, silence = 0;
 
     audio_callback_time = av_gettime_relative();
 
@@ -2541,8 +2540,8 @@ static void sdl_audio_callback(void *opaque, Uint8 *stream, int len)
            audio_size = audio_decode_frame(is);
            if (audio_size < 0) {
                 /* if error, just output silence */
-               is->audio_buf      = is->silence_buf;
-               is->audio_buf_size = sizeof(is->silence_buf) / is->audio_tgt.frame_size * is->audio_tgt.frame_size;
+               silence = 1;
+               is->audio_buf_size = SDL_AUDIO_MIN_BUFFER_SIZE / is->audio_tgt.frame_size * is->audio_tgt.frame_size;
            } else {
                if (is->show_mode != SHOW_MODE_VIDEO)
                    update_sample_display(is, (int16_t *)is->audio_buf, audio_size);
@@ -2553,11 +2552,11 @@ static void sdl_audio_callback(void *opaque, Uint8 *stream, int len)
         len1 = is->audio_buf_size - is->audio_buf_index;
         if (len1 > len)
             len1 = len;
-        if (!is->muted && is->audio_volume == SDL_MIX_MAXVOLUME)
+        if (!is->muted && !silence && is->audio_volume == SDL_MIX_MAXVOLUME)
             memcpy(stream, (uint8_t *)is->audio_buf + is->audio_buf_index, len1);
         else {
-            memset(stream, is->silence_buf[0], len1);
-            if (!is->muted)
+            memset(stream, 0, len1);
+            if (!is->muted && !silence)
                 SDL_MixAudio(stream, (uint8_t *)is->audio_buf + is->audio_buf_index, len1, is->audio_volume);
         }
         len -= len1;