Re: [pulseaudio-discuss] [PATCH] null-source: correct latency report and silence memory

2018-02-15 Thread Georg Chini 

On 15.02.2018 10:07, Raman Shishniou wrote:

On 02/15/2018 10:22 AM, Georg Chini wrote:

On 14.02.2018 23:09, Raman Shishniou wrote:

On 02/15/2018 12:03 AM, Georg Chini wrote:

The null-source currently reports the negative of the correct latency.
Also the memchunk passed to pa_source_post() is not initialized with
silence.

This patch fixes both issues.
---
   src/modules/module-null-source.c | 5 +++--
   1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/modules/module-null-source.c b/src/modules/module-null-source.c
index 41f17bd9..6310bda9 100644
--- a/src/modules/module-null-source.c
+++ b/src/modules/module-null-source.c
@@ -100,7 +100,7 @@ static int source_process_msg(pa_msgobject *o, int code, 
void *data, int64_t off
   pa_usec_t now;
 now = pa_rtclock_now();
-*((int64_t*) data) = (int64_t)u->timestamp - (int64_t)now;
+*((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
 return 0;
   }
@@ -142,8 +142,9 @@ static void thread_func(void *userdata) {
 if ((chunk.length = pa_usec_to_bytes(now - u->timestamp, 
&u->source->sample_spec)) > 0) {
   -chunk.memblock = pa_memblock_new(u->core->mempool, (size_t) 
-1); /* or chunk.length? */
+chunk.memblock = pa_memblock_new(u->core->mempool, 
chunk.length);
   chunk.index = 0;
+pa_silence_memchunk(&chunk, &u->source->sample_spec);
   pa_source_post(u->source, &chunk);
   pa_memblock_unref(chunk.memblock);

I think you need to change the next line too:
-u->timestamp = now;
+u->timestamp += pa_bytes_to_usec(chunk.length, 
&u->source->sample_spec);
   }

to make silence generator more stable



How would that make it more stable? It will only lower the precision of the 
time stamp.

Nope. It will increase the precision. Actually null-source send 
pa_bytes_to_usec(chunk.length)
microseconds of data each iteration which can be smaller than (now - 
u->timestamp).
It must increase timestamp by actually data sent. Accumulated difference will 
be corrected
on the next iteration by sending more data.

For example each 10ms we need to send a 99.5 bytes of data (s8, mono, 9950Hz),
i.e. pa_usec_to_bytes() does: bytes = usecs * 0.00995
and pa_bytes_to_usec() does: usecs = bytes / 0.00995

First iteration:
   u->timestamp == 0
   now = pa_rtclock_now() == 10ms == 1us
   bytes = pa_usec_to_bytes(1 - 0) = 99
   ... send 99 bytes of data ...
   u->timestamp += pa_bytes_to_usec(99) == 9949

Second iteration:
   u->timestamp == 9949
   now = pa_rtclock_now() == 20ms == 2us
   bytes = pa_usec_to_bytes(2 - 9949) = 100
   ... send 100 bytes of data ...
   u->timestamp += pa_bytes_to_used(100) = 9949 + 10050 = 1

Third iteration:
   u->timestamp == 1
   now = pa_rtclock_now() == 30ms == 3us
   bytes = pa_usec_to_bytes(3 - 1) = 99
   ... send 99 bytes of data ...
   u->timestamp += pa_bytes_to_used(99) = 1 + 9949 = 29948

and so on

Current implementation will send only 99 bytes of data each iteration.

--
Raman


Yes, you are right. I thought the timer was set to the real time consumed
by the number of samples generated and not to the specified latency.

I'll correct this, though probably by changing the timer value.

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Re: [pulseaudio-discuss] [PATCH] null-source: correct latency report and silence memory

2018-02-15 Thread Raman Shishniou 
On 02/15/2018 10:22 AM, Georg Chini wrote:
> On 14.02.2018 23:09, Raman Shishniou wrote:
>> On 02/15/2018 12:03 AM, Georg Chini wrote:
>>> The null-source currently reports the negative of the correct latency.
>>> Also the memchunk passed to pa_source_post() is not initialized with
>>> silence.
>>>
>>> This patch fixes both issues.
>>> ---
>>>   src/modules/module-null-source.c | 5 +++--
>>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/modules/module-null-source.c 
>>> b/src/modules/module-null-source.c
>>> index 41f17bd9..6310bda9 100644
>>> --- a/src/modules/module-null-source.c
>>> +++ b/src/modules/module-null-source.c
>>> @@ -100,7 +100,7 @@ static int source_process_msg(pa_msgobject *o, int 
>>> code, void *data, int64_t off
>>>   pa_usec_t now;
>>> now = pa_rtclock_now();
>>> -*((int64_t*) data) = (int64_t)u->timestamp - (int64_t)now;
>>> +*((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
>>> return 0;
>>>   }
>>> @@ -142,8 +142,9 @@ static void thread_func(void *userdata) {
>>> if ((chunk.length = pa_usec_to_bytes(now - u->timestamp, 
>>> &u->source->sample_spec)) > 0) {
>>>   -chunk.memblock = pa_memblock_new(u->core->mempool, 
>>> (size_t) -1); /* or chunk.length? */
>>> +chunk.memblock = pa_memblock_new(u->core->mempool, 
>>> chunk.length);
>>>   chunk.index = 0;
>>> +pa_silence_memchunk(&chunk, &u->source->sample_spec);
>>>   pa_source_post(u->source, &chunk);
>>>   pa_memblock_unref(chunk.memblock);
>> I think you need to change the next line too:
>> -u->timestamp = now;
>> +u->timestamp += pa_bytes_to_usec(chunk.length, 
>> &u->source->sample_spec);
>>   }
>>
>> to make silence generator more stable
>>
>>
> How would that make it more stable? It will only lower the precision of the 
> time stamp.

Nope. It will increase the precision. Actually null-source send 
pa_bytes_to_usec(chunk.length)
microseconds of data each iteration which can be smaller than (now - 
u->timestamp).
It must increase timestamp by actually data sent. Accumulated difference will 
be corrected
on the next iteration by sending more data.

For example each 10ms we need to send a 99.5 bytes of data (s8, mono, 9950Hz),
i.e. pa_usec_to_bytes() does: bytes = usecs * 0.00995
and pa_bytes_to_usec() does: usecs = bytes / 0.00995

First iteration:
  u->timestamp == 0
  now = pa_rtclock_now() == 10ms == 1us
  bytes = pa_usec_to_bytes(1 - 0) = 99
  ... send 99 bytes of data ...
  u->timestamp += pa_bytes_to_usec(99) == 9949

Second iteration:
  u->timestamp == 9949
  now = pa_rtclock_now() == 20ms == 2us
  bytes = pa_usec_to_bytes(2 - 9949) = 100
  ... send 100 bytes of data ...
  u->timestamp += pa_bytes_to_used(100) = 9949 + 10050 = 1

Third iteration:
  u->timestamp == 1
  now = pa_rtclock_now() == 30ms == 3us
  bytes = pa_usec_to_bytes(3 - 1) = 99
  ... send 99 bytes of data ...
  u->timestamp += pa_bytes_to_used(99) = 1 + 9949 = 29948

and so on

Current implementation will send only 99 bytes of data each iteration.

--
Raman
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Re: [pulseaudio-discuss] [PATCH] null-source: correct latency report and silence memory

2018-02-14 Thread Georg Chini 

On 14.02.2018 23:09, Raman Shishniou wrote:

On 02/15/2018 12:03 AM, Georg Chini wrote:

The null-source currently reports the negative of the correct latency.
Also the memchunk passed to pa_source_post() is not initialized with
silence.

This patch fixes both issues.
---
  src/modules/module-null-source.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/modules/module-null-source.c b/src/modules/module-null-source.c
index 41f17bd9..6310bda9 100644
--- a/src/modules/module-null-source.c
+++ b/src/modules/module-null-source.c
@@ -100,7 +100,7 @@ static int source_process_msg(pa_msgobject *o, int code, 
void *data, int64_t off
  pa_usec_t now;
  
  now = pa_rtclock_now();

-*((int64_t*) data) = (int64_t)u->timestamp - (int64_t)now;
+*((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
  
  return 0;

  }
@@ -142,8 +142,9 @@ static void thread_func(void *userdata) {
  
  if ((chunk.length = pa_usec_to_bytes(now - u->timestamp, &u->source->sample_spec)) > 0) {
  
-chunk.memblock = pa_memblock_new(u->core->mempool, (size_t) -1); /* or chunk.length? */

+chunk.memblock = pa_memblock_new(u->core->mempool, 
chunk.length);
  chunk.index = 0;
+pa_silence_memchunk(&chunk, &u->source->sample_spec);
  pa_source_post(u->source, &chunk);
  pa_memblock_unref(chunk.memblock);

I think you need to change the next line too:
  
-u->timestamp = now;

+u->timestamp += pa_bytes_to_usec(chunk.length, 
&u->source->sample_spec);
  }

to make silence generator more stable


How would that make it more stable? It will only lower the precision of 
the time stamp.

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Re: [pulseaudio-discuss] [PATCH] null-source: correct latency report and silence memory

2018-02-14 Thread Raman Shishniou 
On 02/15/2018 12:03 AM, Georg Chini wrote:
> The null-source currently reports the negative of the correct latency.
> Also the memchunk passed to pa_source_post() is not initialized with
> silence.
> 
> This patch fixes both issues.
> ---
>  src/modules/module-null-source.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/src/modules/module-null-source.c 
> b/src/modules/module-null-source.c
> index 41f17bd9..6310bda9 100644
> --- a/src/modules/module-null-source.c
> +++ b/src/modules/module-null-source.c
> @@ -100,7 +100,7 @@ static int source_process_msg(pa_msgobject *o, int code, 
> void *data, int64_t off
>  pa_usec_t now;
>  
>  now = pa_rtclock_now();
> -*((int64_t*) data) = (int64_t)u->timestamp - (int64_t)now;
> +*((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
>  
>  return 0;
>  }
> @@ -142,8 +142,9 @@ static void thread_func(void *userdata) {
>  
>  if ((chunk.length = pa_usec_to_bytes(now - u->timestamp, 
> &u->source->sample_spec)) > 0) {
>  
> -chunk.memblock = pa_memblock_new(u->core->mempool, (size_t) 
> -1); /* or chunk.length? */
> +chunk.memblock = pa_memblock_new(u->core->mempool, 
> chunk.length);
>  chunk.index = 0;
> +pa_silence_memchunk(&chunk, &u->source->sample_spec);
>  pa_source_post(u->source, &chunk);
>  pa_memblock_unref(chunk.memblock);

I think you need to change the next line too:
 
-u->timestamp = now;
+u->timestamp += pa_bytes_to_usec(chunk.length, 
&u->source->sample_spec);
 }

to make silence generator more stable


>  
> 

--
Raman
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[pulseaudio-discuss] [PATCH] null-source: correct latency report and silence memory

2018-02-14 Thread Georg Chini 
The null-source currently reports the negative of the correct latency.
Also the memchunk passed to pa_source_post() is not initialized with
silence.

This patch fixes both issues.
---
 src/modules/module-null-source.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/modules/module-null-source.c b/src/modules/module-null-source.c
index 41f17bd9..6310bda9 100644
--- a/src/modules/module-null-source.c
+++ b/src/modules/module-null-source.c
@@ -100,7 +100,7 @@ static int source_process_msg(pa_msgobject *o, int code, 
void *data, int64_t off
 pa_usec_t now;
 
 now = pa_rtclock_now();
-*((int64_t*) data) = (int64_t)u->timestamp - (int64_t)now;
+*((int64_t*) data) = (int64_t)now - (int64_t)u->timestamp;
 
 return 0;
 }
@@ -142,8 +142,9 @@ static void thread_func(void *userdata) {
 
 if ((chunk.length = pa_usec_to_bytes(now - u->timestamp, 
&u->source->sample_spec)) > 0) {
 
-chunk.memblock = pa_memblock_new(u->core->mempool, (size_t) 
-1); /* or chunk.length? */
+chunk.memblock = pa_memblock_new(u->core->mempool, 
chunk.length);
 chunk.index = 0;
+pa_silence_memchunk(&chunk, &u->source->sample_spec);
 pa_source_post(u->source, &chunk);
 pa_memblock_unref(chunk.memblock);
 
-- 
2.14.1

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