avconv: move audio output buffer allocation to a separate function

Allows for removing a goto and makes the code easier to follow.

avconv.c

@@ -1011,11 +1011,37 @@ static int encode_audio_frame(AVFormatContext *s, OutputStream *ost,
     return pkt.size;
 }
 
+static int alloc_audio_output_buf(AVCodecContext *dec, AVCodecContext *enc,
+                                  int nb_samples)
+{
+    int64_t audio_buf_samples;
+    int audio_buf_size;
+
+    /* calculate required number of samples to allocate */
+    audio_buf_samples = ((int64_t)nb_samples * enc->sample_rate + dec->sample_rate) /
+                        dec->sample_rate;
+    audio_buf_samples = audio_buf_samples * 2 + 10000; // safety factors for the deprecated resampling API
+    audio_buf_samples = FFMAX(audio_buf_samples, enc->frame_size);
+    if (audio_buf_samples > INT_MAX)
+        return AVERROR(EINVAL);
+
+    audio_buf_size = av_samples_get_buffer_size(NULL, enc->channels,
+                                                audio_buf_samples,
+                                                enc->sample_fmt, 32);
+    if (audio_buf_size < 0)
+        return audio_buf_size;
+
+    av_fast_malloc(&audio_buf, &allocated_audio_buf_size, audio_buf_size);
+    if (!audio_buf)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
 static void do_audio_out(AVFormatContext *s, OutputStream *ost,
                          InputStream *ist, AVFrame *decoded_frame)
 {
     uint8_t *buftmp;
-    int64_t audio_buf_size;
 
     int size_out, frame_bytes, resample_changed;
     AVCodecContext *enc = ost->st->codec;
@@ -1024,23 +1050,9 @@ static void do_audio_out(AVFormatContext *s, OutputStream *ost,
     int isize = av_get_bytes_per_sample(dec->sample_fmt);
     uint8_t *buf = decoded_frame->data[0];
     int size     = decoded_frame->nb_samples * dec->channels * isize;
-    int64_t allocated_for_size = size;
-
-need_realloc:
-    audio_buf_size  = (allocated_for_size + isize * dec->channels - 1) / (isize * dec->channels);
-    audio_buf_size  = (audio_buf_size * enc->sample_rate + dec->sample_rate) / dec->sample_rate;
-    audio_buf_size  = audio_buf_size * 2 + 10000; // safety factors for the deprecated resampling API
-    audio_buf_size  = FFMAX(audio_buf_size, enc->frame_size);
-    audio_buf_size *= osize * enc->channels;
-
-    if (audio_buf_size > INT_MAX) {
-        av_log(NULL, AV_LOG_FATAL, "Buffer sizes too large\n");
-        exit_program(1);
-    }
 
-    av_fast_malloc(&audio_buf, &allocated_audio_buf_size, audio_buf_size);
-    if (!audio_buf) {
-        av_log(NULL, AV_LOG_FATAL, "Out of memory in do_audio_out\n");
+    if (alloc_audio_output_buf(dec, enc, decoded_frame->nb_samples) < 0) {
+        av_log(NULL, AV_LOG_FATAL, "Error allocating audio buffer\n");
         exit_program(1);
     }
 
@@ -1128,9 +1140,9 @@ need_realloc:
                         exit_program(1);
                     }
 
-                    if (byte_delta > allocated_for_size - size) {
-                        allocated_for_size = byte_delta + (int64_t)size;
-                        goto need_realloc;
+                    if (alloc_audio_output_buf(dec, enc, decoded_frame->nb_samples + idelta) < 0) {
+                        av_log(NULL, AV_LOG_FATAL, "Error allocating audio buffer\n");
+                        exit_program(1);
                     }
                     ist->is_start = 0;