[PATCH 0/3] adding 705.6/768kHz rates; DSD and 768kHz in aloop
This patch series allows using the loopback driver in modern chains with samplerates up to 768kHz and DSD formats.
The patch "ALSA:pcm: add support for 705.6kHz and 768kHz sample rates" is basically a copy of commit 4cc4531c310e ("ALSA: pcm: add support for 352.8KHz and 384KHz sample rate").
As of loopback performance at 768kHz - in my tests aloop runs OK event at 12MHz samplerate.
Pavel Hofman (3): ALSA:aloop: add DSD formats ALSA:pcm: add support for 705.6kHz and 768kHz sample rates ALSA:aloop: add support for up to 768kHz sample rate
include/sound/pcm.h | 5 +++++ sound/core/pcm_native.c | 2 +- sound/drivers/aloop.c | 9 ++++++--- 3 files changed, 12 insertions(+), 4 deletions(-)
The snd-aloop loopback driver does not modify or access the actual samples in any way, defines no volume or mute controls, it's strictly bitperfect. Therefore DSD formats can be supported without any modification.
Add all DSD formats to the list of supported formats.
Signed-off-by: Pavel Hofman pavel.hofman@ivitera.com --- sound/drivers/aloop.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index 892c4e29c0a3..44ee2a4bc2b0 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -927,7 +927,10 @@ static const struct snd_pcm_hardware loopback_pcm_hardware = SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE | - SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE), + SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE | + SNDRV_PCM_FMTBIT_DSD_U8 | + SNDRV_PCM_FMTBIT_DSD_U16_LE | SNDRV_PCM_FMTBIT_DSD_U16_BE | + SNDRV_PCM_FMTBIT_DSD_U32_LE | SNDRV_PCM_FMTBIT_DSD_U32_BE), .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000, .rate_min = 8000, .rate_max = 192000,
Many modern codecs support 705.6kHz and 768kHz sample rates. Current HW params fail to set 705.6kHz and 768kHz sample rates as these are not in the known-rates list.
Add these new rates to the known-rates list to allow them.
Also add defines in pcm.h so that drivers can use it.
Signed-off-by: Pavel Hofman pavel.hofman@ivitera.com --- include/sound/pcm.h | 5 +++++ sound/core/pcm_native.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 210096f124ee..61c6054618c8 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -120,6 +120,8 @@ struct snd_pcm_ops { #define SNDRV_PCM_RATE_192000 (1U<<12) /* 192000Hz */ #define SNDRV_PCM_RATE_352800 (1U<<13) /* 352800Hz */ #define SNDRV_PCM_RATE_384000 (1U<<14) /* 384000Hz */ +#define SNDRV_PCM_RATE_705600 (1U<<15) /* 705600Hz */ +#define SNDRV_PCM_RATE_768000 (1U<<16) /* 768000Hz */
#define SNDRV_PCM_RATE_CONTINUOUS (1U<<30) /* continuous range */ #define SNDRV_PCM_RATE_KNOT (1U<<31) /* supports more non-continuos rates */ @@ -135,6 +137,9 @@ struct snd_pcm_ops { #define SNDRV_PCM_RATE_8000_384000 (SNDRV_PCM_RATE_8000_192000|\ SNDRV_PCM_RATE_352800|\ SNDRV_PCM_RATE_384000) +#define SNDRV_PCM_RATE_8000_768000 (SNDRV_PCM_RATE_8000_384000|\ + SNDRV_PCM_RATE_705600|\ + SNDRV_PCM_RATE_768000) #define _SNDRV_PCM_FMTBIT(fmt) (1ULL << (__force int)SNDRV_PCM_FORMAT_##fmt) #define SNDRV_PCM_FMTBIT_S8 _SNDRV_PCM_FMTBIT(S8) #define SNDRV_PCM_FMTBIT_U8 _SNDRV_PCM_FMTBIT(U8) diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 0b76e76823d2..521ba56392a0 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -2416,7 +2416,7 @@ static int snd_pcm_hw_rule_sample_bits(struct snd_pcm_hw_params *params,
static const unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100, - 48000, 64000, 88200, 96000, 176400, 192000, 352800, 384000 + 48000, 64000, 88200, 96000, 176400, 192000, 352800, 384000, 705600, 768000 };
const struct snd_pcm_hw_constraint_list snd_pcm_known_rates = {
Many modern codecs support rates up to 768kHz (including DSD1024). Add support for rates up to 768kHz to the loopback driver.
Signed-off-by: Pavel Hofman pavel.hofman@ivitera.com --- sound/drivers/aloop.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index 44ee2a4bc2b0..d6dd4b8c750a 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -931,9 +931,9 @@ static const struct snd_pcm_hardware loopback_pcm_hardware = SNDRV_PCM_FMTBIT_DSD_U8 | SNDRV_PCM_FMTBIT_DSD_U16_LE | SNDRV_PCM_FMTBIT_DSD_U16_BE | SNDRV_PCM_FMTBIT_DSD_U32_LE | SNDRV_PCM_FMTBIT_DSD_U32_BE), - .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000, + .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_768000, .rate_min = 8000, - .rate_max = 192000, + .rate_max = 768000, .channels_min = 1, .channels_max = 32, .buffer_bytes_max = 2 * 1024 * 1024,
On 16. 04. 24 14:17, Pavel Hofman wrote:
This patch series allows using the loopback driver in modern chains with samplerates up to 768kHz and DSD formats.
The patch "ALSA:pcm: add support for 705.6kHz and 768kHz sample rates" is basically a copy of commit 4cc4531c310e ("ALSA: pcm: add support for 352.8KHz and 384KHz sample rate").
As of loopback performance at 768kHz - in my tests aloop runs OK event at 12MHz samplerate.
Reviewed-by: Jaroslav Kysela perex@perex.cz
Note that the kernel patches should go through linux-sound@vger.kernel.org mailing list (see MAINTAINERS) now.
Link: https://lore.kernel.org/alsa-devel/20240416121726.628679-1-pavel.hofman@ivit...
Jaroslav
On Tue, 16 Apr 2024 14:17:23 +0200, Pavel Hofman wrote:
This patch series allows using the loopback driver in modern chains with samplerates up to 768kHz and DSD formats.
The patch "ALSA:pcm: add support for 705.6kHz and 768kHz sample rates" is basically a copy of commit 4cc4531c310e ("ALSA: pcm: add support for 352.8KHz and 384KHz sample rate").
As of loopback performance at 768kHz - in my tests aloop runs OK event at 12MHz samplerate.
Pavel Hofman (3): ALSA:aloop: add DSD formats ALSA:pcm: add support for 705.6kHz and 768kHz sample rates ALSA:aloop: add support for up to 768kHz sample rate
Applied to for-next branch now. Thanks.
Takashi
participants (3)
-
Jaroslav Kysela -
Pavel Hofman -
Takashi Iwai