avcodec/audiotoolboxenc: fix 7.1 channel mapping and sample rate

Both AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK and AV_CHANNEL_LAYOUT_7POINT1
should be mapped to kAudioChannelLayoutTag_AAC_7_1_B, otherwise neither
the back surround channel nor the side surround channel has sound.

aac_at has stricter sample rate than other encoders which should be
spcified to enable auto resampling.

alac with sample rate higher than 38400 will not play on Apple devices,
although higher sample rates are accepted by the encoder

All encoders provided by AudioToolbox can handle 32bit integer samples,
enable that for all encoders.

debian/patches/0078-fix-atenc-layout-samplerate.patch

@@ -0,0 +1,67 @@
+Index: FFmpeg/libavcodec/audiotoolboxenc.c
+===================================================================
+--- FFmpeg.orig/libavcodec/audiotoolboxenc.c
++++ FFmpeg/libavcodec/audiotoolboxenc.c
+@@ -235,8 +235,8 @@ static int get_aac_tag(const AVChannelLa
+         { AV_CHANNEL_LAYOUT_6POINT0,           kAudioChannelLayoutTag_AAC_6_0 },
+         { AV_CHANNEL_LAYOUT_6POINT1,           kAudioChannelLayoutTag_AAC_6_1 },
+         { AV_CHANNEL_LAYOUT_7POINT0,           kAudioChannelLayoutTag_AAC_7_0 },
+-        { AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK, kAudioChannelLayoutTag_AAC_7_1 },
+-        { AV_CHANNEL_LAYOUT_7POINT1,           kAudioChannelLayoutTag_MPEG_7_1_C },
++        { AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK, kAudioChannelLayoutTag_AAC_7_1_B },
++        { AV_CHANNEL_LAYOUT_7POINT1,           kAudioChannelLayoutTag_AAC_7_1_B },
+     };
+     int i;
+
+@@ -633,7 +633,7 @@ static const AVOption options[] = {
+         .version    = LIBAVUTIL_VERSION_INT, \
+     };
+
+-#define FFAT_ENC(NAME, ID, PROFILES, CAPS, CHANNEL_LAYOUTS, CH_LAYOUTS) \
++#define FFAT_ENC(NAME, ID, PROFILES, CAPS, CHANNEL_LAYOUTS, CH_LAYOUTS, SAMPLE_RATES) \
+     FFAT_ENC_CLASS(NAME) \
+     const FFCodec ff_##NAME##_at_encoder = { \
+         .p.name         = #NAME "_at", \
+@@ -650,9 +650,10 @@ static const AVOption options[] = {
+                           AV_CODEC_CAP_ENCODER_FLUSH CAPS, \
+         .p.ch_layouts   = CH_LAYOUTS, \
+         .p.sample_fmts  = (const enum AVSampleFormat[]) { \
+-            AV_SAMPLE_FMT_S16, \
++            AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32,\
+             AV_SAMPLE_FMT_U8,  AV_SAMPLE_FMT_NONE \
+         }, \
++        .p.supported_samplerates = SAMPLE_RATES, \
+         .p.profiles     = PROFILES, \
+         .p.wrapper_name = "at", \
+     };
+@@ -667,15 +668,25 @@ static const AVChannelLayout aac_at_ch_l
+     AV_CHANNEL_LAYOUT_6POINT0,
+     AV_CHANNEL_LAYOUT_6POINT1,
+     AV_CHANNEL_LAYOUT_7POINT0,
++    AV_CHANNEL_LAYOUT_7POINT1,
+     AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK,
+     AV_CHANNEL_LAYOUT_QUAD,
+     AV_CHANNEL_LAYOUT_OCTAGONAL,
+     { 0 },
+ };
+
+-FFAT_ENC(aac,          AV_CODEC_ID_AAC,          aac_profiles, , aac_at_channel_layouts, aac_at_ch_layouts)
++static const int aac_at_sample_rates[9] = {
++    48000, 44100, 32000,24000, 22050, 16000, 12000, 11025, 8000
++};
++
++static const int alac_at_sample_rates[16] = {
++    384000, 352800, 192000, 176400, 96000, 88200, 64000, 48000,
++    44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000
++};
++
++FFAT_ENC(aac,          AV_CODEC_ID_AAC,          aac_profiles, , aac_at_channel_layouts, aac_at_ch_layouts, aac_at_sample_rates)
+ //FFAT_ENC(adpcm_ima_qt, AV_CODEC_ID_ADPCM_IMA_QT, NULL)
+-FFAT_ENC(alac,         AV_CODEC_ID_ALAC,         NULL, , NULL, NULL)
+-FFAT_ENC(ilbc,         AV_CODEC_ID_ILBC,         NULL, , NULL, NULL)
+-FFAT_ENC(pcm_alaw,     AV_CODEC_ID_PCM_ALAW,     NULL, , NULL, NULL)
+-FFAT_ENC(pcm_mulaw,    AV_CODEC_ID_PCM_MULAW,    NULL, , NULL, NULL)
++FFAT_ENC(alac,         AV_CODEC_ID_ALAC,         NULL, , NULL, NULL, alac_at_sample_rates)
++FFAT_ENC(ilbc,         AV_CODEC_ID_ILBC,         NULL, , NULL, NULL, aac_at_sample_rates)
++FFAT_ENC(pcm_alaw,     AV_CODEC_ID_PCM_ALAW,     NULL, , NULL, NULL, NULL)
++FFAT_ENC(pcm_mulaw,    AV_CODEC_ID_PCM_MULAW,    NULL, , NULL, NULL, NULL)

debian/patches/series

@@ -75,3 +75,4 @@
 0075-allow-vpl-qsv-to-init-with-the-legacy-msdk-path.patch
 0076-alway-set-videotoolboxenc-pixel-buffer-info.patch
 0077-add-remove-dovi-hdr10plus-bsf.patch
+0078-fix-atenc-layout-samplerate.patch