alp: convert to new channel layout API

Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/alp.c

@@ -119,18 +119,14 @@ static int alp_read_header(AVFormatContext *s)
     par->codec_id               = AV_CODEC_ID_ADPCM_IMA_ALP;
     par->format                 = AV_SAMPLE_FMT_S16;
     par->sample_rate            = hdr->sample_rate;
-    par->channels               = hdr->num_channels;
 
-    if (hdr->num_channels == 1)
-        par->channel_layout     = AV_CH_LAYOUT_MONO;
-    else if (hdr->num_channels == 2)
-        par->channel_layout     = AV_CH_LAYOUT_STEREO;
-    else
+    if (hdr->num_channels > 2)
         return AVERROR_INVALIDDATA;
 
+    av_channel_layout_default(&par->ch_layout, hdr->num_channels);
     par->bits_per_coded_sample  = 4;
     par->block_align            = 1;
-    par->bit_rate               = par->channels *
+    par->bit_rate               = par->ch_layout.nb_channels *
                                   par->sample_rate *
                                   par->bits_per_coded_sample;
 
@@ -148,7 +144,7 @@ static int alp_read_packet(AVFormatContext *s, AVPacket *pkt)
 
     pkt->flags         &= ~AV_PKT_FLAG_CORRUPT;
     pkt->stream_index   = 0;
-    pkt->duration       = ret * 2 / par->channels;
+    pkt->duration       = ret * 2 / par->ch_layout.nb_channels;
 
     return 0;
 }
@@ -202,7 +198,7 @@ static int alp_write_init(AVFormatContext *s)
         return AVERROR(EINVAL);
     }
 
-    if (par->channels > 2) {
+    if (par->ch_layout.nb_channels > 2) {
         av_log(s, AV_LOG_ERROR, "A maximum of 2 channels are supported\n");
         return AVERROR(EINVAL);
     }
@@ -228,7 +224,7 @@ static int alp_write_header(AVFormatContext *s)
     avio_wl32(s->pb,  alp->type == ALP_TYPE_PCM ? 12 : 8);
     avio_write(s->pb, "ADPCM", 6);
     avio_w8(s->pb,    0);
-    avio_w8(s->pb,    par->channels);
+    avio_w8(s->pb,    par->ch_layout.nb_channels);
     if (alp->type == ALP_TYPE_PCM)
         avio_wl32(s->pb, par->sample_rate);