audio: drop swapped-endian audio formats

Until now, the audio chain could handle both little endian and big
endian formats. This actually doesn't make much sense, since the audio
API and the HW will most likely prefer native formats. Or at the very
least, it should be trivial for audio drivers to do the byte swapping
themselves.

From now on, the audio chain contains native-endian formats only. All
AOs and some filters are adjusted. af_convertsignendian.c is now wrongly
named, but the filter name is adjusted. In some cases, the audio
infrastructure was reused on the demuxer side, but that is relatively
easy to rectify.

This is a quite intrusive and radical change. It's possible that it will
break some things (especially if they're obscure or not Linux), so watch
out for regressions. It's probably still better to do it the bulldozer
way, since slow transition and researching foreign platforms would take
a lot of time and effort.

1 files changed, 32 insertions, 44 deletions

diff --git a/audio/out/ao_sdl.c b/audio/out/ao_sdl.c
index 9af5db4021..d2362a723e 100644
--- a/audio/out/ao_sdl.c
+++ b/audio/out/ao_sdl.c
@@ -38,6 +38,20 @@ struct priv
     float buflen;
 };
 
+static int fmtmap[][2] = {
+    {AF_FORMAT_U8,      AUDIO_U8},
+    {AF_FORMAT_S8,      AUDIO_S8},
+    {AF_FORMAT_U16,     AUDIO_U16SYS},
+    {AF_FORMAT_S16,     AUDIO_S16SYS},
+#ifdef AUDIO_S32SYS
+    {AF_FORMAT_S32,     AUDIO_S32SYS},
+#endif
+#ifdef AUDIO_F32SYS
+    {AF_FORMAT_FLOAT,   AUDIO_F32SYS},
+#endif
+    {0}
+};
+
 static void audio_callback(void *userdata, Uint8 *stream, int len)
 {
     struct ao *ao = userdata;
@@ -104,26 +118,12 @@ static int init(struct ao *ao)
 
     SDL_AudioSpec desired, obtained;
 
-    switch (ao->format) {
-        case AF_FORMAT_U8: desired.format = AUDIO_U8; break;
-        case AF_FORMAT_S8: desired.format = AUDIO_S8; break;
-        case AF_FORMAT_U16_LE: desired.format = AUDIO_U16LSB; break;
-        case AF_FORMAT_U16_BE: desired.format = AUDIO_U16MSB; break;
-        default:
-        case AF_FORMAT_S16_LE: desired.format = AUDIO_S16LSB; break;
-        case AF_FORMAT_S16_BE: desired.format = AUDIO_S16MSB; break;
-#ifdef AUDIO_S32LSB
-        case AF_FORMAT_S32_LE: desired.format = AUDIO_S32LSB; break;
-#endif
-#ifdef AUDIO_S32MSB
-        case AF_FORMAT_S32_BE: desired.format = AUDIO_S32MSB; break;
-#endif
-#ifdef AUDIO_F32LSB
-        case AF_FORMAT_FLOAT_LE: desired.format = AUDIO_F32LSB; break;
-#endif
-#ifdef AUDIO_F32MSB
-        case AF_FORMAT_FLOAT_BE: desired.format = AUDIO_F32MSB; break;
-#endif
+    desired.format = AUDIO_S16SYS;
+    for (int n = 0; fmtmap[n][0]; n++) {
+        if (ao->format == fmtmap[n][0]) {
+            desired.format = fmtmap[n][1];
+            break;
+        }
     }
     desired.freq = ao->samplerate;
     desired.channels = ao->channels.num;
@@ -156,30 +156,18 @@ static int init(struct ao *ao)
     // large, this will help.
     ao->device_buffer = 3 * obtained.samples;
 
-    switch (obtained.format) {
-        case AUDIO_U8: ao->format = AF_FORMAT_U8; break;
-        case AUDIO_S8: ao->format = AF_FORMAT_S8; break;
-        case AUDIO_S16LSB: ao->format = AF_FORMAT_S16_LE; break;
-        case AUDIO_S16MSB: ao->format = AF_FORMAT_S16_BE; break;
-        case AUDIO_U16LSB: ao->format = AF_FORMAT_U16_LE; break;
-        case AUDIO_U16MSB: ao->format = AF_FORMAT_U16_BE; break;
-#ifdef AUDIO_S32LSB
-        case AUDIO_S32LSB: ao->format = AF_FORMAT_S32_LE; break;
-#endif
-#ifdef AUDIO_S32MSB
-        case AUDIO_S32MSB: ao->format = AF_FORMAT_S32_BE; break;
-#endif
-#ifdef AUDIO_F32LSB
-        case AUDIO_F32LSB: ao->format = AF_FORMAT_FLOAT_LE; break;
-#endif
-#ifdef AUDIO_F32MSB
-        case AUDIO_F32MSB: ao->format = AF_FORMAT_FLOAT_BE; break;
-#endif
-        default:
-            if (!ao->probing)
-                MP_ERR(ao, "could not find matching format\n");
-            uninit(ao);
-            return -1;
+    ao->format = 0;
+    for (int n = 0; fmtmap[n][0]; n++) {
+        if (obtained.format == fmtmap[n][1]) {
+            ao->format = fmtmap[n][0];
+            break;
+        }
+    }
+    if (!ao->format) {
+        if (!ao->probing)
+            MP_ERR(ao, "could not find matching format\n");
+        uninit(ao);
+        return -1;
     }
 
     if (!ao_chmap_sel_get_def(ao, &sel, &ao->channels, obtained.channels)) {