@@ -119,7 +119,7 @@ static int alac_set_info(ALACContext *alac)

     alac->setinfo_rice_historymult      = *ptr++;

     alac->setinfo_rice_initialhistory   = *ptr++;

     alac->setinfo_rice_kmodifier        = *ptr++;

-    ptr++;                         /* channels? */

+    alac->numchannels                   = *ptr++;

     bytestream_get_be16(&ptr);      /* ??? */

     bytestream_get_be32(&ptr);      /* max coded frame size */

     bytestream_get_be32(&ptr);      /* bitrate ? */

@@ -456,10 +456,9 @@ static int alac_decode_frame(AVCodecContext *avctx,

     init_get_bits(&alac->gb, inbuffer, input_buffer_size * 8);

     channels = get_bits(&alac->gb, 3) + 1;

-    if (channels > MAX_CHANNELS) {

-        av_log(avctx, AV_LOG_ERROR, "channels > %d not supported\n",

-               MAX_CHANNELS);

-        return -1;

+    if (channels != avctx->channels) {

+        av_log(avctx, AV_LOG_ERROR, "frame header channel count mismatch\n");

+        return AVERROR_INVALIDDATA;

     }

     /* 2^result = something to do with output waiting.

@@ -634,7 +633,6 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)

 {

     ALACContext *alac = avctx->priv_data;

     alac->avctx = avctx;

-    alac->numchannels = alac->avctx->channels;

     /* initialize from the extradata */

     if (alac->avctx->extradata_size != ALAC_EXTRADATA_SIZE) {

@@ -657,6 +655,21 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)

              return -1;

     }

+    if (alac->numchannels < 1) {

+        av_log(avctx, AV_LOG_WARNING, "Invalid channel count\n");

+        alac->numchannels = avctx->channels;

+    } else {

+        if (alac->numchannels > MAX_CHANNELS)

+            alac->numchannels = avctx->channels;

+        else

+            avctx->channels = alac->numchannels;

+    }

+    if (avctx->channels > MAX_CHANNELS) {

+        av_log(avctx, AV_LOG_ERROR, "Unsupported channel count: %d\n",

+               avctx->channels);

+        return AVERROR_PATCHWELCOME;

+    }

+

     return 0;

 }