[alsa-devel] snd_pcm_set_params faild on set_buffer_time_near and set_period_time_near
Hallo,
I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1
and input params was:
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL
unfortunately, this function fails, on function snd_pcm_hw_param_set_first:
ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are:
snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
because in snd_pcm_hw_param_set_near is
if (last) err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); if (err < 0) dump_hw_params(params, "set_near", var, *val, err); return err;
and in error part is only debug output and not restore original parameters.
Environment: alsa-lib 1.0.27.1 TI AM335x soc
Simple fix is attached, but I am not sure if it is correct.
BR Martin Geier
I tried to configure alsa device with snd_pcm_set_params function,
requested
parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
The function snd_pcm_set_params does not always succed especially you are using 22050Hz which is 20ms increment
Which soc driver ? It is quite difficult to find the soutce by chip name
https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/soc
I am using 'davinci' soc driver with board specific driver.
On 23.07.2015 09:19, Raymond Yau wrote:
I tried to configure alsa device with snd_pcm_set_params function,
requested
parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
The function snd_pcm_set_params does not always succed especially you are using 22050Hz which is 20ms increment
Which soc driver ? It is quite difficult to find the soutce by chip name
https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/soc
On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote:
Hallo,
I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1
and input params was:
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL
unfortunately, this function fails, on function snd_pcm_hw_param_set_first:
ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are:
snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
because in snd_pcm_hw_param_set_near is
if (last) err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); if (err < 0) dump_hw_params(params, "set_near", var, *val, err); return err;
and in error part is only debug output and not restore original parameters.
Environment: alsa-lib 1.0.27.1 TI AM335x soc
Simple fix is attached, but I am not sure if it is correct.
Thanks for analysis and patch. It's however rather a bug in snd_pcm_set_params(). There is no guarantee to keep the old value in snd_pcm_set_*(), thus the caller needs to take care of it instead.
Takashi
Thanks for help,
in attachment is patch with suggest change. Is the patch acceptable?
Martin
On 23.07.2015 10:11, Takashi Iwai wrote:
On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote:
Hallo,
I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1
and input params was:
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL
unfortunately, this function fails, on function snd_pcm_hw_param_set_first:
ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are:
snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
because in snd_pcm_hw_param_set_near is
if (last) err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); if (err < 0) dump_hw_params(params, "set_near", var, *val, err); return err;
and in error part is only debug output and not restore original parameters.
Environment: alsa-lib 1.0.27.1 TI AM335x soc
Simple fix is attached, but I am not sure if it is correct.
Thanks for analysis and patch. It's however rather a bug in snd_pcm_set_params(). There is no guarantee to keep the old value in snd_pcm_set_*(), thus the caller needs to take care of it instead.
Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
On Fri, 24 Jul 2015 09:52:14 +0200, Martin Geier wrote:
Thanks for help,
in attachment is patch with suggest change. Is the patch acceptable?
I prefer a bit clearer name like params_saved or such, but yes, it's what I had in my mind, too. Could you tidy it up and resubmit with the more description -- why it's needed and what does it? Last but not least, it'd be helpful if you give also signed-off-by tag.
thanks,
Takashi
Martin
On 23.07.2015 10:11, Takashi Iwai wrote:
On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote:
Hallo,
I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1
and input params was:
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL
unfortunately, this function fails, on function snd_pcm_hw_param_set_first:
ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are:
snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
because in snd_pcm_hw_param_set_near is
if (last) err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); if (err < 0) dump_hw_params(params, "set_near", var, *val, err); return err;
and in error part is only debug output and not restore original parameters.
Environment: alsa-lib 1.0.27.1 TI AM335x soc
Simple fix is attached, but I am not sure if it is correct.
Thanks for analysis and patch. It's however rather a bug in snd_pcm_set_params(). There is no guarantee to keep the old value in snd_pcm_set_*(), thus the caller needs to take care of it instead.
Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
-- *StreamUnlimited* High Tech Campus Vienna, Gutheil-Schoder-Gasse 10, A-1102 Vienna, Austria Levocska 9, 851 01 Bratislava, Slovakia Email: martin.geier@streamunlimited.com www.streamunlimited.com
Meet us at: IFA - Berlin, 4-9 September 2015 HK Electronics - Hong Kong, 13-16 October 2015 CEDIA - Dallas, 14-17 October 2015 [1.2 <text/html; windows-1252 (7bit)>]
From 2d4e94d974678bbd4826b33c59c275d1f34edc20 Mon Sep 17 00:00:00 2001
From: Martin Geier martin.geier@streamunlimited.com Date: Fri, 24 Jul 2015 09:30:57 +0200 Subject: [PATCH] restore hw params on set rate failed
pcm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index ca4d416..b6de73e 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -7883,7 +7883,7 @@ int snd_pcm_set_params(snd_pcm_t *pcm, int soft_resample, unsigned int latency) {
snd_pcm_hw_params_t *params;
snd_pcm_hw_params_t *params, pparams; snd_pcm_sw_params_t *swparams; const char *s = snd_pcm_stream_name(snd_pcm_stream(pcm)); snd_pcm_uframes_t buffer_size, period_size;@@ -7936,9 +7936,11 @@ int snd_pcm_set_params(snd_pcm_t *pcm, return -EINVAL; } /* set the buffer time */
- pparams = *params; err = INTERNAL(snd_pcm_hw_params_set_buffer_time_near)(pcm, params, &latency, NULL); if (err < 0) { /* error path -> set period size as first */
*params = pparams; /* set the period time */ period_time = latency / 4; err = INTERNAL(snd_pcm_hw_params_set_period_time_near)(pcm, params, &period_time, NULL);-- 1.9.1
Patch with fixed name and description.
Martin
On 24.07.2015 10:21, Takashi Iwai wrote:
On Fri, 24 Jul 2015 09:52:14 +0200, Martin Geier wrote:
Thanks for help,
in attachment is patch with suggest change. Is the patch acceptable?
I prefer a bit clearer name like params_saved or such, but yes, it's what I had in my mind, too. Could you tidy it up and resubmit with the more description -- why it's needed and what does it? Last but not least, it'd be helpful if you give also signed-off-by tag.
thanks,
Takashi
Martin
On 23.07.2015 10:11, Takashi Iwai wrote:
On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote:
Hallo,
I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1
and input params was:
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL
unfortunately, this function fails, on function snd_pcm_hw_param_set_first:
ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are:
snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
because in snd_pcm_hw_param_set_near is
if (last) err = snd_pcm_hw_param_set_last(pcm, params, var, val, dir); else err = snd_pcm_hw_param_set_first(pcm, params, var, val, dir); if (err < 0) dump_hw_params(params, "set_near", var, *val, err); return err;
and in error part is only debug output and not restore original parameters.
Environment: alsa-lib 1.0.27.1 TI AM335x soc
Simple fix is attached, but I am not sure if it is correct.
Thanks for analysis and patch. It's however rather a bug in snd_pcm_set_params(). There is no guarantee to keep the old value in snd_pcm_set_*(), thus the caller needs to take care of it instead.
Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
-- *StreamUnlimited* High Tech Campus Vienna, Gutheil-Schoder-Gasse 10, A-1102 Vienna, Austria Levocska 9, 851 01 Bratislava, Slovakia Email: martin.geier@streamunlimited.com www.streamunlimited.com
Meet us at: IFA - Berlin, 4-9 September 2015 HK Electronics - Hong Kong, 13-16 October 2015 CEDIA - Dallas, 14-17 October 2015 [1.2 <text/html; windows-1252 (7bit)>]
From 2d4e94d974678bbd4826b33c59c275d1f34edc20 Mon Sep 17 00:00:00 2001
From: Martin Geier martin.geier@streamunlimited.com Date: Fri, 24 Jul 2015 09:30:57 +0200 Subject: [PATCH] restore hw params on set rate failed
pcm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index ca4d416..b6de73e 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -7883,7 +7883,7 @@ int snd_pcm_set_params(snd_pcm_t *pcm, int soft_resample, unsigned int latency) {
snd_pcm_hw_params_t *params;
snd_pcm_hw_params_t *params, pparams; snd_pcm_sw_params_t *swparams; const char *s = snd_pcm_stream_name(snd_pcm_stream(pcm)); snd_pcm_uframes_t buffer_size, period_size;@@ -7936,9 +7936,11 @@ int snd_pcm_set_params(snd_pcm_t *pcm, return -EINVAL; } /* set the buffer time */
- pparams = *params; err = INTERNAL(snd_pcm_hw_params_set_buffer_time_near)(pcm, params, &latency, NULL); if (err < 0) { /* error path -> set period size as first */
*params = pparams; /* set the period time */ period_time = latency / 4; err = INTERNAL(snd_pcm_hw_params_set_period_time_near)(pcm, params, &period_time, NULL);-- 1.9.1
2015-07-24 19:16 GMT+08:00 Martin Geier martin.geier@streamunlimited.com:
Patch with fixed name and description.
Martin
On 24.07.2015 10:21, Takashi Iwai wrote:
On Fri, 24 Jul 2015 09:52:14 +0200, Martin Geier wrote:
Thanks for help,
in attachment is patch with suggest change. Is the patch acceptable?
I prefer a bit clearer name like params_saved or such, but yes, it's what I had in my mind, too. Could you tidy it up and resubmit with the more description -- why it's needed and what does it? Last but not least, it'd be helpful if you give also signed-off-by tag.
thanks,
Takashi
Martin
On 23.07.2015 10:11, Takashi Iwai wrote:
On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote:
Hallo,
I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000
Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1
and input params was:
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL
unfortunately, this function fails, on function snd_pcm_hw_param_set_first:
ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are:
snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL
What is the period time and buffer time after applied your patch ?
Are latency always <= 50ms ?
Hi Raymond,
Output parameters with custom logs: set_buffer_time_near: -22 set period time: 12517 get period size: 276 set buffer size: 1104 get buffer size: 1104
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (12517 12518) PERIOD_SIZE: 276 PERIOD_BYTES: 1104 PERIODS: 4 BUFFER_TIME: (50068 50069) BUFFER_SIZE: 1104 BUFFER_BYTES: 4416
What do you mean, are latency always <= 50ms? In what cases?
Martin
On 25.07.2015 04:01, Raymond Yau wrote:
2015-07-24 19:16 GMT+08:00 Martin Geier <martin.geier@streamunlimited.com mailto:martin.geier@streamunlimited.com>:
Patch with fixed name and description. Martin On 24.07.2015 10:21, Takashi Iwai wrote: On Fri, 24 Jul 2015 09:52:14 +0200, Martin Geier wrote: Thanks for help, in attachment is patch with suggest change. Is the patch acceptable? I prefer a bit clearer name like params_saved or such, but yes, it's what I had in my mind, too. Could you tidy it up and resubmit with the more description -- why it's needed and what does it? Last but not least, it'd be helpful if you give also signed-off-by tag. thanks, Takashi Martin On 23.07.2015 10:11, Takashi Iwai wrote: On Tue, 21 Jul 2015 10:52:01 +0200, Martin Geier wrote: Hallo, I tried to configure alsa device with snd_pcm_set_params function, requested parameters was: channel 2, rate: 22050, soft_resample: 1, latency: 50000 Function snd_pcm_hw_params_set_buffer_time_near and snd_pcm_hw_param_set_near is called with: min: 50000, max: 50000, mindir: 0, maxdir: -1 and input params was: ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (362 743039) PERIOD_SIZE: [8 16384] PERIOD_BYTES: [32 65536] PERIODS: [2 19] BUFFER_TIME: (725 1486078) BUFFER_SIZE: [16 32768] BUFFER_BYTES: [64 131072] TICK_TIME: ALL unfortunately, this function fails, on function snd_pcm_hw_param_set_first: ALSA ERROR hw_params: set_near (BUFFER_TIME) value = 50000 : Invalid argument ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALL This shouldn't be problem because in snd_pcm_set_params is snd_pcm_hw_params_set_period_time_near called. This function should be called with same params as snd_pcm_hw_params_set_buffer_time_near but the input params are: snd_pcm_hw_param_set_near: min: 12500, max: 12500, mindir: 0, maxdir: -1 hw_params: snd_pcm_hw_param_set_near (PERIOD_TIME) ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (4580 5533) PERIOD_SIZE: NONE PERIOD_BYTES: [404 488] PERIODS: 10 BUFFER_TIME: (50022 50023) BUFFER_SIZE: 1103 BUFFER_BYTES: 4412 TICK_TIME: ALLWhat is the period time and buffer time after applied your patch ?
Are latency always <= 50ms ?
2015-7-27 下午3:12於 "Martin Geier" martin.geier@streamunlimited.com寫道：
Hi Raymond,
Output parameters with custom logs: set_buffer_time_near: -22 set period time: 12517 get period size: 276 set buffer size: 1104 get buffer size: 1104
ACCESS: RW_INTERLEAVED FORMAT: S16_LE SUBFORMAT: STD SAMPLE_BITS: 16 FRAME_BITS: 32 CHANNELS: 2 RATE: 22050 PERIOD_TIME: (12517 12518) PERIOD_SIZE: 276 PERIOD_BYTES: 1104 PERIODS: 4 BUFFER_TIME: (50068 50069) BUFFER_SIZE: 1104 BUFFER_BYTES: 4416
What do you mean, are latency always <= 50ms? In what cases?
http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#ga45d50841b...
Set the hardware and software parameters in a simple way. Parameters:pcm PCM handle format required PCM format access required PCM access channels required PCM channels rate required sample rate in Hz soft_resample 0 = disallow alsa-lib resample stream, 1 = allow resampling latency required overall latency in us
Refer to your result seem latency only close to 50ms
participants (3)
-
Martin Geier -
Raymond Yau -
Takashi Iwai