Re: [Alsa-devel] PCM Params
ok paul i had another look at the driver playback/capture tutorials. I have one question.Do applicationsinitialize and use a pcm_handle of the alsa driver when they begin interaction with it?Surely not I thought that the driver would work totally independently of my VoIP and this is why I asked the question is it possible to change driver parameters directly. Brian. Paul Davis [EMAIL PROTECTED] wrote: Im running OpenH323 a voice over ip application.What Iwere you asking about this on alsa-devel a couple of weeks ago?have found out from using it is that the alsa driveralways puts 32 msecs(256 bytes) of data into thesender buffer, or takes the same amount from thereceiver buffer.32 msecs is driver default if it's not set by theapplication? I thought if i change the relevantdefault params in alsa-driver/alsa-kernel/ andrecompile, it wud do the trick. ...Instead i should include this function call to setthe driver period..snd_pcm_hw_params_set_period_size()within my OpenH323 app with relevant header files???yes, although i am not sure you understand enough about how this allworks. and i am pretty sure i don't have time to explain. did you readeither o! f the tutorials on the ALSA site for programmers? Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now
[Alsa-devel] PCM Params
Hi , i'm trying to change the fragment size that the alsa driver is capturing/playing out. It's currently set at 32 msecs(256 bytes). They are set in the runtime structure... runtime-period_max ...etc Could anybody tell me which file these parameters are set in the alsa-driver directory? Thanks, Brian. Yahoo! Messenger - Communicate instantly...Ping your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html --- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149alloc_id=8166op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] PCM Params
--- Paul Davis [EMAIL PROTECTED] wrote: Hi , i'm trying to change the fragment size that the alsa driver is capturing/playing out. It's currently set at 32 msecs(256 bytes). They are set in the runtime structure... runtime-period_max ...etc Could anybody tell me which file these parameters are set in the alsa-driver directory? you should be using snd_pcm_hw_params_set_period_size() Does this mean that i can change the period size without recompiling the driver? Im am not developing an ALSA application myself, just trying to change the pcm parameters. snd_pcm_hw_params_set_period_size()...looks like a function call included in a user written ALSA application?? Excuse me if this is a stupid questions but,How do I use this function call in my case to change the driver period?? Brian. Yahoo! Messenger - Communicate instantly...Ping your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html --- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149alloc_id=8166op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] alsa driver data rates
Hi James, Im asking you becuae looking thru the archives you asked a similar question a long time ago.i'm using an open source VoIP application with thealsa driver. My card is the onboard intel8x0. My problem is figuring out the patterns I amgetting with the alsa driver when transmittingpackets.For instance when I use the GSM codec with a packetssize of 80 msecs and 132 bytes, packets aretransmitted at alternate intervals of 64/96 msecs.When i use G.711 packets of 240 bytes are transmitted every 32 msecs with an extra packet every 15 pkts. With G.711 it is obvious that 256 bytes are added to driver sending buffer every 32 msecs.However this does not match for GSM because it needs only 132 bytes every 64/96 msecs. Can the driver change the amount of data it gets from the soundcard to suit the codec? Help appreciated,Brian.James Courtier-Dutton [EMAIL PROTECTED] wrote: Brian Furey wrote: Hi all, I have an intel810 onboard soundcard.I am using the alsa driver with a VoIP session. The intel8x0.c file has a minimum period byte size of 32 bytes with the minimum no. of periods being 1.The min and max rate is set to 48k. How can I find out what actual(runtime) size period the alsa driver is dealing with? Does it use the minimum size as the period size? Brian. Brian, I am working on a VoIP setup. I am updating the asterisk alsa console driver so that it actually works! The current driver is stuck round about alsa api 0.5.xThe period size that the sound card is actually using does not really matter, if just effects latency. The bigger the period size, the higher the latency.Just set the period size to t he smallest the sound card can do, and then just read and write to it.I found that PLAYBACK and CAPTURE directions can have different period sizes, so it is better to open separate handles for playback and capture.In the config setup, you set the buffer and period sizes, and before you set them, you can retrieve the current min/max period and buffer sizes.For playback, it is best to have a certain minimum buffer being full most of the time, due to network jitter, and this buffer can act as the jitter buffer. The actual size of this is probably best found out from trial and error (I have not finished testing this bit yet).For capture, just poll for input, and then read whatever is in the capture buffer and transmit it. You can experiment with different methods of early buffer reads, but again, I have not finished testing with that, so I can't give you any definite answers.Another thing to test with could be sampling and playback at 48k.Most sound cards work at 48k, and this would reduce the period_time. (period_size stays the same, but as one is using a higher rate, the period_time decreases, and thus latency.) The problems with that is that most VoIP is at 8k, so some resampling is required.CheersJames---This SF.Net email is sponsored by: IBM Linux TutorialsFree Linux tutorial presented by Daniel Robbins, President and CEO ofGenToo technologies. Learn everything from fundamentals to systemadministration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click___Alsa-devel mailing list[EMAIL PROTECTED]https://lists.sourceforge.net/lists/listinfo/alsa-devel Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now
[Alsa-devel] alsa substreams +rates
Hi All, with the ALSA driver, what do the OSS substream mean?If you have a 2 main capture channels, how many substream would you have? Also the capture stream is supposed to operate at 8000 Hz per second.Is it possible that it is actually say 8192, a value to the power-of-two? How can I find this out? Brian. Yahoo! Messenger - Communicate instantly...Ping your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html --- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
[Alsa-devel] periods,packets and driver patterns not to mention patience!!!
Hi All, i'm using an open source VoIP application with the alsa driver. My card is the onboard intel8x0. My problem is figuring out the patterns I am getting with the alsa driver when transmitting packets. For instance when I use the GSM codec with a packets size of 80 msecs and 132 bytes, packets are transmitted at alternate intervals of 64/96 msecs. When I configure the codec so the packet size is 128 bytes(power-of-two) and still 80 msecs, packets are still transmitted at 64/96 msecs. Now when i configure the codec so packet size is 132 bytes and 64 msces, packets are transmitted every 64 msces. Given that the alsa driv interrupts at period boundaries(which are defined in bytes), the tests i have carried out prove otherwise..i.e that the driver operates in millisecond power-of-two based periods. ?? Help appreciated, Brian. Yahoo! Messenger - Communicate instantly...Ping your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html --- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] alsa driver
Jaroslav, Busy system cant explain something as consequent as this. When the packet size being transmitted is 30 msecs(240bytes) or 32 msecs(240bytes), the OpenH323 app sends packets every 32 msecs. When the packet size is 80 msecs(132 bytes), the OpenH323 app sends packets at alternate intervals of 64 msecs and 96 msecs.Both are multiples of 32 msecs. Surely it's to do with the period size being added to the driver sending buffer. The thing is I have got all the info about the period size,no of periods ..etc but it's not adding up yet. Brian.Jaroslav Kysela [EMAIL PROTECTED] wrote: On Tue, 6 Apr 2004, Brian Furey wrote: Hi all, i'm running the alsa-driver-1.0.0. Im using it with the OpenH323 application. Packets are transmitted or received in 32 millisecond intervals or multiples of 32 millisecond intervals. For example using the G711 codec, packets are transmitted every 32 milliseconds. For the GSM-06.10 codec, packets are transmitted at alternate intervals of 64 milliseconds or 96 milliseconds. Why is this?Busy system?Jaroslav-Jaroslav Kysela <[EMAIL PROTECTED]>Linux Kernel Sound MaintainerALSA Project, SuSE Labs---This SF.Net email is sponsored by: IBM Linux TutorialsFree Linux tutorial presented by Daniel Robbins, President and CEO ofGenToo technologies. Le! arn everything from fundamentals to systemadministration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click___Alsa-devel mailing list[EMAIL PROTECTED]https://lists.sourceforge.net/lists/listinfo/alsa-devel Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now
[Alsa-devel] Driver hardw + softw parameters
Hi All, still trying to get the hardware and software runtime paramters of the driver... In alsa-driver*/alsa-kernel/core there is the pcm.c file. There are 2 functions in this file snd_pcm_substream_proc_hw_params_read and snd_pcm_substream_proc_sw_params_read Both of these print out to some output source the information I need using i.e. snd_iprintf(buffer, period_size: %lu\n, runtime-period_size); snd_iprintf is in /alsa-driver/alsa-kernel/info.c I traced this snd_iprintf function and it passes its data in a buffer to the function vsnprintf(..). Could someone enlighten me as to where it write to...console, file, temporary storage thanx, Brian. ___ WIN FREE WORLDWIDE FLIGHTS - nominate a cafe in the Yahoo! Mail Internet Cafe Awards www.yahoo.co.uk/internetcafes --- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] intel8x0.c
Thanks James, i'm using the GSM-06.10 codec with my VoIP application.The frame rate is 160 timestamp units or 20 millisecond frames.4 frames are added to a packet and transmitted. Packets are transmitted at alternate intervals of 64 and 96 milliseconds. This is due to the soundcard driver and the period sizes being read into the buffer.Can the period size the driver is capturing from the soundcard and putting into the sending buffer change during execution of a VoIP session or is it fixed.Given that I have not changed it, what is the default period size for the ALSA driver? I'm basically trying to find out the reason packets are transmitted at alternate intervals of 64 and 96 millisecondsand the runtime period size is the key help appreciated, brian. --- James Courtier-Dutton [EMAIL PROTECTED] wrote: Brian Furey wrote: Hi all, I have an intel810 onboard soundcard.I am using the alsa driver with a VoIP session. The intel8x0.c file has a minimum period byte size of 32 bytes with the minimum no. of periods being 1.The min and max rate is set to 48k. How can I find out what actual(runtime) size period the alsa driver is dealing with? Does it use the minimum size as the period size? Brian. Brian, I am working on a VoIP setup. I am updating the asterisk alsa console driver so that it actually works! The current driver is stuck round about alsa api 0.5.x The period size that the sound card is actually using does not really matter, if just effects latency. The bigger the period size, the higher the latency. Just set the period size to the smallest the sound card can do, and then just read and write to it. I found that PLAYBACK and CAPTURE directions can have different period sizes, so it is better to open separate handles for playback and capture. In the config setup, you set the buffer and period sizes, and before you set them, you can retrieve the current min/max period and buffer sizes. For playback, it is best to have a certain minimum buffer being full most of the time, due to network jitter, and this buffer can act as the jitter buffer. The actual size of this is probably best found out from trial and error (I have not finished testing this bit yet). For capture, just poll for input, and then read whatever is in the capture buffer and transmit it. You can experiment with different methods of early buffer reads, but again, I have not finished testing with that, so I can't give you any definite answers. Another thing to test with could be sampling and playback at 48k. Most sound cards work at 48k, and this would reduce the period_time. (period_size stays the same, but as one is using a higher rate, the period_time decreases, and thus latency.) The problems with that is that most VoIP is at 8k, so some resampling is required. Cheers James ___ WIN FREE WORLDWIDE FLIGHTS - nominate a cafe in the Yahoo! Mail Internet Cafe Awards www.yahoo.co.uk/internetcafes --- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
[Alsa-devel] intel8x0.c
Hi all, I have an intel810 onboard soundcard.I am using the alsa driver with a VoIP session. The intel8x0.c file has a minimum period byte size of 32 bytes with the minimum no. of periods being 1.The min and max rate is set to 48k. How can I find out what actual(runtime) size period the alsa driver is dealing with? Does it use the minimum size as the period size? Brian. ___ WIN FREE WORLDWIDE FLIGHTS - nominate a cafe in the Yahoo! Mail Internet Cafe Awards www.yahoo.co.uk/internetcafes --- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
Re: [Alsa-devel] intel8x0.c
Right Jaroslav, that means i would modify intel8x0.c to include a call to snd_pcm_hw_params_get_period_size() or snd_pcm_hw_params_get_period_time() in the appropriate place. Write the values returned say to a text file. Recompile the ALsa driver and re-insert it into the kernel.Start my application and check contents of text file. Am I right in saying this? Thanks in advance, Brian. --- Jaroslav Kysela [EMAIL PROTECTED] wrote: On Tue, 30 Mar 2004, Brian Furey wrote: Hi all, I have an intel810 onboard soundcard.I am using the alsa driver with a VoIP session. The intel8x0.c file has a minimum period byte size of 32 bytes with the minimum no. of periods being 1.The min and max rate is set to 48k. How can I find out what actual(runtime) size period the alsa driver is dealing with? After the snd_pcm_hw_params() call, the given hardware parameter container will have the chosen period size or snd_pcm_hw_params_current() creates the current hw_params container. Then use snd_pcm_hw_params_get_period_size() or snd_pcm_hw_params_get_period_time(). Jaroslav - Jaroslav Kysela [EMAIL PROTECTED] Linux Kernel Sound Maintainer ALSA Project, SuSE Labs ___ WIN FREE WORLDWIDE FLIGHTS - nominate a cafe in the Yahoo! Mail Internet Cafe Awards www.yahoo.co.uk/internetcafes --- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click ___ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
RE: [Alsa-devel] Current Hardware Parameter Settings
Thanks Giuliano, How can I get a dump of the current hardware configuration space?I have the ALSA driver 1.0.0 installed on my Redhat 9 Machine. Brian.Giuliano Pochini [EMAIL PROTECTED] wrote: On 24-Mar-2004 Brian Furey wrote: Hi all, im using the ALSA driver 1.0.0 on two linux machines that connect a voice-over-ip session. I need to know the minimum fragment size that the alsa driver can take from the soundcard and place in the sending/receiving buffer. Does it depend on the speed that the soundcard is operating at?It may depend on any thing. Set buffer size and periodsize with one of these and use the value they return:snd_pcm_hw_params_set_buffer_size_near()snd_pcm_hw_params_set_period_size_near()snd_pcm_hw_params_set_buffer_time_near()snd_pcm_hw_params_set_period_time_near()Look here for more infos:http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___h_w___params.html--Giuliano.---This SF.Net email is sponsored by: IBM Linux TutorialsFree Linux tutorial presented by Daniel Robbins, President and CEO ofGenToo technologies. Learn everything from fundamentals to systemadministration.http://ads.osdn.com/?ad_id=1470alloc_id=3638op=click___Alsa-devel mailing list[EMAIL PROTECTED]https://lists.sourceforge.net/lists/listinfo/alsa-devel Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now
[Alsa-devel] Minimum Period-(Fragment) Size
Hi all, im using the ALSA driver 1.0.0 on two linux machines that connect a voice-over-ip session. I need to know the minimum fragment size that the alsa drivercan take from the soundcard and place in the sending/receiving buffer.Does it depend on the speed that the soundcard is operating at? Any help appreciated, Brian. Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now
