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| author | Jurgen Kramer <gtmkramer@xs4all.nl> | 2012-04-01 11:10:12 +0200 |
|---|---|---|
| committer | Max Kellermann <max@duempel.org> | 2012-04-04 20:13:15 +0200 |
| commit | f930f37d35995f0fc07f70aefc41babc0db1757e (patch) | |
| tree | ebb54621fef2c4c73ec5bcd760acaccdc91414bf /src/pcm_dsd_usb.c | |
| parent | 4feb57e8953d114b85abd3910b477ef58ef171ae (diff) | |
| download | mpd-f930f37d35995f0fc07f70aefc41babc0db1757e.tar.gz mpd-f930f37d35995f0fc07f70aefc41babc0db1757e.tar.xz mpd-f930f37d35995f0fc07f70aefc41babc0db1757e.zip | |
Add support for DSD-over-USB version 1.0, remove pre-v1 support
Diffstat (limited to 'src/pcm_dsd_usb.c')
| -rw-r--r-- | src/pcm_dsd_usb.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/src/pcm_dsd_usb.c b/src/pcm_dsd_usb.c index 976420c00..4b5e39f39 100644 --- a/src/pcm_dsd_usb.c +++ b/src/pcm_dsd_usb.c @@ -24,11 +24,19 @@ G_GNUC_CONST static inline uint32_t -pcm_two_dsd_to_usb(uint8_t a, uint8_t b) +pcm_two_dsd_to_usb_marker1(uint8_t a, uint8_t b) { - return 0xffaa0000 | (a << 8) | b; + return 0xff050000 | (a << 8) | b; } +G_GNUC_CONST +static inline uint32_t +pcm_two_dsd_to_usb_marker2(uint8_t a, uint8_t b) +{ + return 0xfffa0000 | (a << 8) | b; +} + + const uint32_t * pcm_dsd_to_usb(struct pcm_buffer *buffer, unsigned channels, const uint8_t *src, size_t src_size, @@ -53,12 +61,27 @@ pcm_dsd_to_usb(struct pcm_buffer *buffer, unsigned channels, uint32_t *const dest0 = pcm_buffer_get(buffer, dest_size), *dest = dest0; - for (unsigned i = num_frames; i > 0; --i) { + for (unsigned i = num_frames / 2; i > 0; --i) { + for (unsigned c = channels; c > 0; --c) { + /* each 24 bit sample has 16 DSD sample bits + plus the magic 0x05 marker */ + + *dest++ = pcm_two_dsd_to_usb_marker1(src[0], src[channels]); + + /* seek the source pointer to the next + channel */ + ++src; + } + + /* skip the second byte of each channel, because we + have already copied it */ + src += channels; + for (unsigned c = channels; c > 0; --c) { /* each 24 bit sample has 16 DSD sample bits - plus the magic 0xaa marker */ + plus the magic 0xfa marker */ - *dest++ = pcm_two_dsd_to_usb(src[0], src[channels]); + *dest++ = pcm_two_dsd_to_usb_marker2(src[0], src[channels]); /* seek the source pointer to the next channel */ |