Re: [fpc-pascal] How to use pipes ?
Huh, sorry to monopolize but... I get it. ;-) Changing the built-in read-callback method with this: function OpusReadCB(stream: Pointer; var buffer; nbytes: cint): cint; cdecl; begin if nbytes<>0 then result := TInputPipeStream(stream^).read(Buffer, nbytes) else result := 0; end; Does the tick. This is real web-streaming, for hours in super-high quality ! Many thanks to everybody for helping in this (hard) battle. I will clean the code and commit it asap. fpc always win. Fre;D - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538p5727554.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
Re-hello. Some more news: OK, I make work a other method: op_open_callbacks(InPipe, op_callbacks, BufferURL[0], PipeBufferSize, err); This method use a named pipe and can be use of the box with Andrew's THttpgetter. No need to do complicated conversion of pipe into buffer. op_callbacks does it for you. Nice, it works, but just like with op_open_memory, only 2 seconds of music then it stops. The same reason: op_read_float => result after 2 seconds : Outframes = 0. Houlala, I feel that we are near the goal. Fre;D - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538p5727553.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
Hello Jose. >The fact that op_read_float is zero is not an error, simply the amount of samples read by opus engine is zero Exactly. I know that isnot a error otherwise OutFrames < 0. >simply the amount of samples read by opus engine is zero. Exactly too and this because my conversion pipe into buffer is wrong. I never worked with pipes and, to be honest, I do not get everything... How to translate it to a "classical" buffer of a memory stream... IMO, my code did read all the file from internet after +- 10 loops, the main buffer of the pipe is full. I am in the dark, the mechanism of pipes escape to me. Otherwise, many thanks to make me discover Opus. It seems really the universal audio format. And open source. One of the developers is the one who created SoundFile library (a must). Fre;D - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538p5727552.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] question about fphttpclient
On Wed, 1 Feb 2017, Ched wrote: Dear All, I use with great success (and pleasure!) the unit fphttpclient under winxp, mageia and raspbian with some code like WITH TFPHTTPCLIENT.CREATE(NIL) DO BEGIN REP:=GET(REQ); FREE; END; after having defined REQ (+initialisation with some url) and REP as ansistring's. To download text and html pages, that works very nice. My questions : - Can I use the same code to download binary data like gzipped files with no "chance" that the content is translated to a special codepage ? Yes. - How can I have access to the date and size informations on the server side ? These are reported in the headers. Michael. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] question about fphttpclient
Dear All, I use with great success (and pleasure!) the unit fphttpclient under winxp, mageia and raspbian with some code like WITH TFPHTTPCLIENT.CREATE(NIL) DO BEGIN REP:=GET(REQ); FREE; END; after having defined REQ (+initialisation with some url) and REP as ansistring's. To download text and html pages, that works very nice. My questions : - Can I use the same code to download binary data like gzipped files with no "chance" that the content is translated to a special codepage ? - How can I have access to the date and size informations on the server side ? Kindest regards, Ched' ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] destructor
As I understand this: It may sometimes well be necessary to write your own destructor to clean up. But if you do this, don't call it foo; call it destructor and override it: destructor destroy; override; In your own destructor method, don't forget to call inherited in the end. -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/destructor-tp5727426p5727549.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] for loop vs while loop
Just a note - I learned that for very short "for" loops it may be even a bit faster to count downwards (to zero) rather than upwards if possible, because the comparison to zero is very effiicient. Not sure though whether that still makes a difference on modern processors. -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/for-loop-vs-while-loop-tp5727537p5727548.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
El 01/02/2017 a las 19:55, fredvs escribió: Outframes := op_read_float(HandleOP, @Buffer[0], FramesWanted , nil); if Outframes = 0 then exit; Hello, if OutFrames < 0 then exit; The fact that op_read_float is zero is not an error, simply the amount of samples read by opus engine is zero, maybe because internal buffer is full and do not need more data by now. Reading from internet is usually faster than playing bitrate. Maybe you should sleep for a bit and retry. From docs: Returns: The number of samples read per channel on success, or a negative value on failure. -- ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
Ho Andrew, nice to read you. ;-) I battle hard to use your Thttpgetter for Opus, like you did for mpg123. The difference with mpg123 is that Opus needs a buffer (mpg123 a named pipe). I am nearly sure that the problem comes from my code to get the buffer from the pipe: while (outst2 < FramesWanted) and (outst > 0) do begin outst := InPipe.Read(BufferTemp[0],FramesWanted-outst2); if outst > 0 then for i := 0 to outst -1 do BufferURL[i+outst2] := BufferTemp[i] ; outst2 := outst2 + outst; end; > Where is it stopping? In the main loop, it is stopping a legal way, after +- 10 loops, because Outframes = 0: Outframes := op_read_float(HandleOP, @Buffer[0], FramesWanted , nil); if Outframes = 0 then exit; > You are blocking processing data but the buffer from the kernel is full. > On many Linux pc's the kernel buffer size is 65536 bytes. Yes, it seems that this is the problem (but how to solve that?) Thanks. Fre;D - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538p5727546.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
On 02/01/2017 08:52 AM, fredvs wrote: Hello. Some more explanation. With that code, only +- 10 loops are working, after, no more Ouframes... why ? Where is it stopping? It may be that you are asking for more bytes than are available and it is blocking waiting for more data. Or the opposite could be true. You are blocking processing data but the buffer from the kernel is full. On many Linux pc's the kernel buffer size is 65536 bytes. Regards, Andrew ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
Hello. Some more explanation. With that code, only +- 10 loops are working, after, no more Ouframes... why ? const FramesWanted : 640; PipeBufferSize : 10240; BufferURL, BufferTemp : tbytes; BufferFloat : array of float; ... setlength(BufferURL, PipeBufferSize); setlength(BufferTemp, FramesWanted * 2); setlength(BufferFloat, FramesWanted * 2); CreatePipeHandles(InHandle, OutHandle, PipeBufferSize); InPipe := TInputPipeStream.Create(InHandle); OutPipe := TOutputPipeStream.Create(OutHandle); HandleOP := op_test_memory(BufferURL[0],PipeBufferSize, Err); Outframes := 1; outst := 1; outst2 := 0; // The loop, is it the correct way ? while Outframes > 0 do begin while (outst2 < FramesWanted) and (outst > 0) do begin outst := InPipe.Read(BufferTemp[0],FramesWanted-outst2); if outst > 0 then for i := 0 to outst -1 do BufferURL[i+outst2] := BufferTemp[i] ; outst2 := outst2 + outst; end; // Outframes > 0 only +- 10 loops, why ? Outframes := op_read_float(HandleOP, @Buffer[0], FramesWanted , nil)); ... end; Thanks. Fre;D - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538p5727544.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
Many thanks Mattias. Huh, and about bytesavailable ? See here: CreatePipeHandles(InHandle, OutHandle, PipeBufferSize); InPipe := TInputPipeStream.Create(InHandle); OutPipe := TOutputPipeStream.Create(OutHandle); httpget := TThreadHttpGetter.Create(url, OutPipe); // is length ok ? setlength(BufferURL, PipeBufferSize); setlength(buffertemp, PipeBufferSize); // Is it the right way to fill BufferURL ? len := 1 ; len2 := 0 ; while (len2 < PipeBufferSize) and (len > 0) do begin len := InPipe.Read(buffertemp[0],PipeBufferSize-len2); if len > 0 then for i := 0 to len -1 do BufferURL[i+len2] := buffertemp[i] ; len2 := len2 + len; end; Thanks. - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538p5727543.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to use pipes ?
On Wed, 1 Feb 2017 05:02:05 -0700 (MST) fredvs wrote: > Hello. > > I have done lot of search on internet about pipes without success. > Even for Delphi. no demo nor explanation. > The same in fpc wki page. > > For example, how to use bytesavailable with pipes ? http://wiki.freepascal.org/Executing_External_Programs#How_to_redirect_output_with_TProcess > In: > CreatePipeHandles(InHandle, OutHandle, APipeBufferSize); > > InPipe.Read(Bufferout[0],BPipeBufferSize); > > What is the the ratio with APipeBufferSize vs BPipeBufferSize ? APipeBufferSize is how much the other process can produce before congestion. BPipeBufferSize is how much you want to process/eat each iteration. Usually APipeBufferSize >= BPipeBufferSize. > And length of Bufferout[0] vs APipeBufferSize vs BPipeBufferSize ? Bufferout[0] is just the first value. The whole Bufferout can be written by InPipe.Read. Therefore Bufferout must be >= BPipeBufferSize. > In short, a demo will be welcome. Mattias ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] for loop vs while loop
Am 2017-02-01 um 12:49 schrieb Graeme Geldenhuys: > Just curious (been in a discussion with somebody else). Is there a > performance difference between a FOR loop and a WHILE loop? > Not sure if it will make a difference, but the usage is with three > nested loops, iterating over some 300,000 plus data points in total. I think that in general a FOR loop *can* be faster than a WHILE loop because the iterator variable will be held in a register (if possible) and its start and end values will be calculated only once. Also, because the iterator variable will be incremented (or decremented) by a constant value it helps the compiler to speed it up further. If the major time of the loop is needed for the loop body it will not make much difference of course. Still it makes sense to always use a FOR loop if possible. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] for loop vs while loop
On 2017-02-01 12:12, Mattias Gaertner wrote: > Yes, for-loop calculates the end value only once. Ah, thanks for that. Seems so obvious now. :) Regards, Graeme ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] for loop vs while loop
On Wed, 1 Feb 2017 11:49:34 + Graeme Geldenhuys wrote: > Hi, > > Just curious (been in a discussion with somebody else). Is there a > performance difference between a FOR loop and a WHILE loop? Yes, for-loop calculates the end value only once. > Not sure if it will make a difference, but the usage is with three > nested loops, iterating over some 300,000 plus data points in total. Mattias ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] How to use pipes ?
Hello. I have done lot of search on internet about pipes without success. Even for Delphi. no demo nor explanation. The same in fpc wki page. For example, how to use bytesavailable with pipes ? In: CreatePipeHandles(InHandle, OutHandle, APipeBufferSize); InPipe.Read(Bufferout[0],BPipeBufferSize); What is the the ratio with APipeBufferSize vs BPipeBufferSize ? And length of Bufferout[0] vs APipeBufferSize vs BPipeBufferSize ? In short, a demo will be welcome. Fre;D - Many thanks ;-) -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-use-pipes-tp5727538.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] for loop vs while loop
Hi, Just curious (been in a discussion with somebody else). Is there a performance difference between a FOR loop and a WHILE loop? Not sure if it will make a difference, but the usage is with three nested loops, iterating over some 300,000 plus data points in total. Regards, Graeme ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
