diff options
| -rw-r--r-- | src/pcm/pcm.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index 7ec1f0e5..ca4d416f 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -7361,6 +7361,13 @@ OBSOLETE1(snd_pcm_sw_params_get_silence_size, ALSA_0.9, ALSA_0.9.0rc4); #endif /* DOC_HIDDEN */ +static int chmap_equal(const snd_pcm_chmap_t *a, const snd_pcm_chmap_t *b) +{ + if (a->channels != b->channels) + return 0; + return !memcmp(a->pos, b->pos, a->channels * sizeof(a->pos[0])); +} + /** * \!brief Query the available channel maps * \param pcm PCM handle to query @@ -7415,6 +7422,10 @@ snd_pcm_chmap_t *snd_pcm_get_chmap(snd_pcm_t *pcm) */ int snd_pcm_set_chmap(snd_pcm_t *pcm, const snd_pcm_chmap_t *map) { + const snd_pcm_chmap_t *oldmap = snd_pcm_get_chmap(pcm); + if (oldmap && chmap_equal(oldmap, map)) + return 0; + if (!pcm->ops->set_chmap) return -ENXIO; return pcm->ops->set_chmap(pcm, map); |