Fixed avcodec audio decoder after API behavior change.

It fixes at least WMAP decoding.

modules/codec/avcodec/audio.c

@@ -306,6 +306,14 @@ aout_buffer_t * DecodeAudio ( decoder_t *p_dec, block_t **pp_block )
         return NULL;
     }
 
+    *pp_block = p_block = block_Realloc( p_block, 0, p_block->i_buffer + FF_INPUT_BUFFER_PADDING_SIZE );
+    if( !p_block )
+        return NULL;
+    p_block->i_buffer -= FF_INPUT_BUFFER_PADDING_SIZE;
+    memset( &p_block->p_buffer[p_block->i_buffer], 0, FF_INPUT_BUFFER_PADDING_SIZE );
+
+    do
+    {
         i_output = __MAX( p_block->i_buffer, p_sys->i_output_max );
         if( i_output > p_sys->i_output_max )
         {
@@ -313,12 +321,6 @@ aout_buffer_t * DecodeAudio ( decoder_t *p_dec, block_t **pp_block )
             p_sys->p_output = av_realloc( p_sys->p_output, i_output );
         }
 
-    *pp_block = p_block = block_Realloc( p_block, 0, p_block->i_buffer + FF_INPUT_BUFFER_PADDING_SIZE );
-    if( !p_block )
-        return NULL;
-    p_block->i_buffer -= FF_INPUT_BUFFER_PADDING_SIZE;
-    memset( &p_block->p_buffer[p_block->i_buffer], 0, FF_INPUT_BUFFER_PADDING_SIZE );
-
 #if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT( 52, 0, 0 )
         i_used = avcodec_decode_audio2( p_sys->p_context,
                                        (int16_t*)p_sys->p_output, &i_output,
@@ -346,6 +348,8 @@ aout_buffer_t * DecodeAudio ( decoder_t *p_dec, block_t **pp_block )
         p_block->i_buffer -= i_used;
         p_block->p_buffer += i_used;
 
+    } while( p_block->i_buffer > 0 && i_output <= 0 );
+
     if( p_sys->p_context->channels <= 0 || p_sys->p_context->channels > 8 ||
         p_sys->p_context->sample_rate <= 0 )
     {