lavr: add a public function for setting a custom channel map

This allows reordering, duplication, and silencing of input channels.

1 files changed, 29 insertions, 3 deletions

diff --git a/libavresample/audio_data.c b/libavresample/audio_data.c
index 199a68cb11..c52f518e9a 100644
--- a/libavresample/audio_data.c
+++ b/libavresample/audio_data.c
@@ -213,7 +213,7 @@ void ff_audio_data_free(AudioData **a)
     av_freep(a);
 }
 
-int ff_audio_data_copy(AudioData *dst, AudioData *src)
+int ff_audio_data_copy(AudioData *dst, AudioData *src, ChannelMapInfo *map)
 {
     int ret, p;
 
@@ -221,6 +221,11 @@ int ff_audio_data_copy(AudioData *dst, AudioData *src)
     if (dst->sample_fmt != src->sample_fmt || dst->channels < src->channels)
         return AVERROR(EINVAL);
 
+    if (map && !src->is_planar) {
+        av_log(src, AV_LOG_ERROR, "cannot remap packed format during copy\n");
+        return AVERROR(EINVAL);
+    }
+
     /* if the input is empty, just empty the output */
     if (!src->nb_samples) {
         dst->nb_samples = 0;
@@ -233,8 +238,29 @@ int ff_audio_data_copy(AudioData *dst, AudioData *src)
         return ret;
 
     /* copy data */
-    for (p = 0; p < src->planes; p++)
-        memcpy(dst->data[p], src->data[p], src->nb_samples * src->stride);
+    if (map) {
+        if (map->do_remap) {
+            for (p = 0; p < src->planes; p++) {
+                if (map->channel_map[p] >= 0)
+                    memcpy(dst->data[p], src->data[map->channel_map[p]],
+                           src->nb_samples * src->stride);
+            }
+        }
+        if (map->do_copy || map->do_zero) {
+            for (p = 0; p < src->planes; p++) {
+                if (map->channel_copy[p])
+                    memcpy(dst->data[p], dst->data[map->channel_copy[p]],
+                           src->nb_samples * src->stride);
+                else if (map->channel_zero[p])
+                    av_samples_set_silence(&dst->data[p], 0, src->nb_samples,
+                                           1, dst->sample_fmt);
+            }
+        }
+    } else {
+        for (p = 0; p < src->planes; p++)
+            memcpy(dst->data[p], src->data[p], src->nb_samples * src->stride);
+    }
+
     dst->nb_samples = src->nb_samples;
 
     return 0;