diff options
author | Dana Conrad <dconrad@fastmail.com> | 2021-08-09 19:22:52 -0500 |
---|---|---|
committer | Solomon Peachy <pizza@shaftnet.org> | 2021-08-12 10:07:49 +0000 |
commit | 6de6e1459de28bef919b869ee757474c615cb787 (patch) | |
tree | ecf10a64809863d1cc3626a3b92dec856b937c4e | |
parent | 235e41578be60135c8ad682e05440a5b9142ce69 (diff) | |
download | rockbox-6de6e1459de28bef919b869ee757474c615cb787.tar.gz rockbox-6de6e1459de28bef919b869ee757474c615cb787.zip |
Eros Q Hosted: Apply DC Bias to PCM Data
Similar to the native port, the hosted port benefits from
adding a -1 dc bias to the PCM data. This prevents almost
all clicking artifacts.
Change-Id: Ic6378716774b6d88df23c476e2ef54d49f33dc72
-rw-r--r-- | firmware/export/erosqlinux_codec.h | 2 | ||||
-rw-r--r-- | firmware/target/hosted/pcm-alsa.c | 9 |
2 files changed, 9 insertions, 2 deletions
diff --git a/firmware/export/erosqlinux_codec.h b/firmware/export/erosqlinux_codec.h index b6ab58fa74..2ed1ae11cf 100644 --- a/firmware/export/erosqlinux_codec.h +++ b/firmware/export/erosqlinux_codec.h | |||
@@ -3,6 +3,8 @@ | |||
3 | 3 | ||
4 | #define AUDIOHW_CAPS (LINEOUT_CAP) | 4 | #define AUDIOHW_CAPS (LINEOUT_CAP) |
5 | 5 | ||
6 | #define PCM_DC_OFFSET_VALUE -1 | ||
7 | |||
6 | AUDIOHW_SETTING(VOLUME, "dB", 0, 2, -74, 0, -40) | 8 | AUDIOHW_SETTING(VOLUME, "dB", 0, 2, -74, 0, -40) |
7 | 9 | ||
8 | //#define AUDIOHW_NEEDS_INITIAL_UNMUTE | 10 | //#define AUDIOHW_NEEDS_INITIAL_UNMUTE |
diff --git a/firmware/target/hosted/pcm-alsa.c b/firmware/target/hosted/pcm-alsa.c index 13ebbbcbeb..68002d8158 100644 --- a/firmware/target/hosted/pcm-alsa.c +++ b/firmware/target/hosted/pcm-alsa.c | |||
@@ -68,6 +68,11 @@ | |||
68 | #warning "MIX_FRAME_SAMPLES <1024 may cause dropouts!" | 68 | #warning "MIX_FRAME_SAMPLES <1024 may cause dropouts!" |
69 | #endif | 69 | #endif |
70 | 70 | ||
71 | /* PCM_DC_OFFSET_VALUE is a workaround for eros q hardware quirk */ | ||
72 | #if !defined(PCM_DC_OFFSET_VALUE) | ||
73 | # define PCM_DC_OFFSET_VALUE 0 | ||
74 | #endif | ||
75 | |||
71 | static const snd_pcm_access_t access_ = SND_PCM_ACCESS_RW_INTERLEAVED; /* access mode */ | 76 | static const snd_pcm_access_t access_ = SND_PCM_ACCESS_RW_INTERLEAVED; /* access mode */ |
72 | #if defined(HAVE_ALSA_32BIT) | 77 | #if defined(HAVE_ALSA_32BIT) |
73 | static const snd_pcm_format_t format = SND_PCM_FORMAT_S32_LE; /* sample format */ | 78 | static const snd_pcm_format_t format = SND_PCM_FORMAT_S32_LE; /* sample format */ |
@@ -359,8 +364,8 @@ static bool copy_frames(bool first) | |||
359 | sample_t *sample_ptr = &frames[2*(period_size-frames_left)]; | 364 | sample_t *sample_ptr = &frames[2*(period_size-frames_left)]; |
360 | for (int i = 0; i < nframes; i++) | 365 | for (int i = 0; i < nframes; i++) |
361 | { | 366 | { |
362 | *sample_ptr++ = *pcm_ptr++ * dig_vol_mult_l; | 367 | *sample_ptr++ = (*pcm_ptr++ * dig_vol_mult_l) + PCM_DC_OFFSET_VALUE; |
363 | *sample_ptr++ = *pcm_ptr++ * dig_vol_mult_r; | 368 | *sample_ptr++ = (*pcm_ptr++ * dig_vol_mult_r) + PCM_DC_OFFSET_VALUE; |
364 | } | 369 | } |
365 | } | 370 | } |
366 | else | 371 | else |