From 5b1a06b1c9c596b3c406ea632a252dcccbee25ed Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefasab@gmail.com>
Date: Fri, 28 Oct 2011 18:44:28 +0200
Subject: [PATCH] libmp3lame: log error message in case of invalid number of
 channels

Also return meaningful error number in place of -1.
Improve feedback.
---
 libavcodec/libmp3lame.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/libavcodec/libmp3lame.c b/libavcodec/libmp3lame.c
index fcefa2915e..b540362d5c 100644
--- a/libavcodec/libmp3lame.c
+++ b/libavcodec/libmp3lame.c
@@ -49,8 +49,11 @@ static av_cold int MP3lame_encode_init(AVCodecContext *avctx)
 {
     Mp3AudioContext *s = avctx->priv_data;
 
-    if (avctx->channels > 2)
-        return -1;
+    if (avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR,
+               "Invalid number of channels %d, must be <= 2\n", avctx->channels);
+        return AVERROR(EINVAL);
+    }
 
     s->stereo = avctx->channels > 1 ? 1 : 0;