From 282255bbd21815ef6471298ce9e3422b58984678 Mon Sep 17 00:00:00 2001
From: Justin Ruggles <justin.ruggles@gmail.com>
Date: Tue, 14 Dec 2010 14:52:40 +0000
Subject: [PATCH] Split setting of bandwidth into a separate function.

Originally committed as revision 25984 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/ac3enc.c | 54 ++++++++++++++++++++++++++++-----------------
 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index 6adc11f83c..296c156832 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -1294,13 +1294,45 @@ static av_cold int validate_options(AVCodecContext *avctx, AC3EncodeContext *s)
 }
 
 
+/**
+ * Set bandwidth for all channels.
+ * The user can optionally supply a cutoff frequency. Otherwise an appropriate
+ * default value will be used.
+ */
+static av_cold void set_bandwidth(AC3EncodeContext *s, int cutoff)
+{
+    int ch, bw_code;
+
+    if (cutoff) {
+        /* calculate bandwidth based on user-specified cutoff frequency */
+        int fbw_coeffs;
+        cutoff         = av_clip(cutoff, 1, s->sample_rate >> 1);
+        fbw_coeffs     = cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
+        bw_code        = av_clip((fbw_coeffs - 73) / 3, 0, 60);
+    } else {
+        /* use default bandwidth setting */
+        /* XXX: should compute the bandwidth according to the frame
+           size, so that we avoid annoying high frequency artifacts */
+        bw_code = 50;
+    }
+
+    /* set number of coefficients for each channel */
+    for (ch = 0; ch < s->fbw_channels; ch++) {
+        s->bandwidth_code[ch] = bw_code;
+        s->nb_coefs[ch]       = bw_code * 3 + 73;
+    }
+    if (s->lfe_on)
+        s->nb_coefs[s->lfe_channel] = 7; /* LFE channel always has 7 coefs */
+}
+
+
 /**
  * Initialize the encoder.
  */
 static av_cold int ac3_encode_init(AVCodecContext *avctx)
 {
     AC3EncodeContext *s = avctx->priv_data;
-    int ch, bw_code, ret;
+    int ret;
 
     avctx->frame_size = AC3_FRAME_SIZE;
 
@@ -1318,25 +1350,7 @@ static av_cold int ac3_encode_init(AVCodecContext *avctx)
     s->samples_written = 0;
     s->frame_size      = s->frame_size_min;
 
-    /* set bandwidth */
-    if (avctx->cutoff) {
-        /* calculate bandwidth based on user-specified cutoff frequency */
-        int cutoff     = av_clip(avctx->cutoff, 1, s->sample_rate >> 1);
-        int fbw_coeffs = cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
-        bw_code        = av_clip((fbw_coeffs - 73) / 3, 0, 60);
-    } else {
-        /* use default bandwidth setting */
-        /* XXX: should compute the bandwidth according to the frame
-           size, so that we avoid annoying high frequency artifacts */
-        bw_code = 50;
-    }
-    for (ch = 0; ch < s->fbw_channels; ch++) {
-        /* bandwidth for each channel */
-        s->bandwidth_code[ch] = bw_code;
-        s->nb_coefs[ch]       = bw_code * 3 + 73;
-    }
-    if (s->lfe_on)
-        s->nb_coefs[s->lfe_channel] = 7; /* LFE channel always has 7 coefs */
+    set_bandwidth(s, avctx->cutoff);
 
     /* initial snr offset */
     s->coarse_snr_offset = 40;