Bug#1081666: fix compilation of moc against ffmpeg 7

[Nicola Ferralis]

package: moc
Version: 1:2.6.0~svn-r3005-3.1build6

The source code of moc is incompatible with the current version of 
FFmpeg 7, leading to a crash when trying to compile against it.

The attached patch fixes the issues, allowing successful compilation.
diff -Nru moc-2.6.0~svn-r3005.orig/decoder_plugins/ffmpeg/ffmpeg.c 
moc-2.6.0~svn-r3005/decoder_plugins/ffmpeg/ffmpeg.c
--- moc-2.6.0~svn-r3005.orig/decoder_plugins/ffmpeg/ffmpeg.c    2024-09-13 
12:06:30.475572948 -0400
+++ moc-2.6.0~svn-r3005/decoder_plugins/ffmpeg/ffmpeg.c 2024-09-13 
12:30:30.759312936 -0400
@@ -562,10 +562,10 @@
 /* Downmix multi-channel audios to stereo. */
 static void set_downmixing (struct ffmpeg_data *data)
 {
-       if (av_get_channel_layout_nb_channels (data->enc->channel_layout) <= 2)
+       if (av_get_channel_layout_nb_channels (data->enc->ch_layout) <= 2)
                return;
 
-       data->enc->request_channel_layout = AV_CH_LAYOUT_STEREO;
+       av_channel_layout_copy (&data->enc->ch_layout, AV_CH_LAYOUT_STEREO);
 }
 
 static int ffmpeg_io_read_cb (void *s, uint8_t *buf, int count)
@@ -1128,16 +1128,16 @@
                is_planar = av_sample_fmt_is_planar (data->enc->sample_fmt);
                packed = (char *)frame->extended_data[0];
                packed_size = frame->nb_samples * data->sample_width
-                                               * data->enc->channels;
+                                               * 
data->enc->ch_layout.nb_channels;
 
-               if (is_planar && data->enc->channels > 1) {
+               if (is_planar && data->enc->ch_layout.nb_channels > 1) {
                        int sample, ch;
 
                        packed = xmalloc (packed_size);
 
                        for (sample = 0; sample < frame->nb_samples; sample += 
1) {
-                               for (ch = 0; ch < data->enc->channels; ch += 1)
-                                       memcpy (packed + (sample * 
data->enc->channels + ch)
+                               for (ch = 0; ch < 
data->enc->ch_layout.nb_channels; ch += 1)
+                                       memcpy (packed + (sample * 
data->enc->ch_layout.nb_channels + ch)
                                                                 * 
data->sample_width,
                                                (char 
*)frame->extended_data[ch] + sample * data->sample_width,
                                                data->sample_width);
@@ -1235,7 +1235,7 @@
                return 0;
 
        /* FFmpeg claims to always return native endian. */
-       sound_params->channels = data->enc->channels;
+       sound_params->channels = data->enc->ch_layout.nb_channels;
        sound_params->rate = data->enc->sample_rate;
        sound_params->fmt = data->fmt | SFMT_NE;