[SOLVED] UOS: play from TMemoryStream

[Fred vS]

he virtual file is not a general concept

And it is also a concept that I will not use.

It seems to me something for hackers (you know those people who prefer to use their brain to steal vs to create).

uos_AddFromMemory(...) uses a array of float as memory stream.

Up to the user to create that input from what he want.

Fre;D

[molly]

he virtual file is not a general concept

And it is also a concept that I will not use.

It seems to me something for hackers (you know those people who prefer to use their brain to steal vs to create).

uos_AddFromMemory(...) uses a array of float as memory stream.

Up to the user to create that input from what he want.

Fre;D

I am a bit flabbergasted by that response.

I'm sure it is all due to the language barrier but, for sure there isn't anything hackish about a library (such as libsndfile) offering functionality to implement a virtual backend that can be used to load and save data.

Libraries like libsndfile provide such feature in order to let their functionality integrated independent of the programming language being used.

That allows for better integration in the programming language, in case things can not be done using the 'normal' offered functions to accomplish the task.

In that regards it is nothing more then adding events to a form. If you don't implement the event then you do not use that functionality if you do use the event then you've added support for it. f.e. handling mouse-clicks.

FPC makes heavy use of streams, simply because it allows a simple more or less uniform way whether a user wishes to load something from a file, memory, the internet or whatever the stream retrieve it data from.

Components/classes like zipstream, structured storage and resource streams are a good example of allowing the user to store their data in whatever stream format and offer a uniform way to extract data from those streams.

uos_AddFromMemory(...) uses a array of float as memory stream.

While that is a good start, it still does not allow for the user to use what he/she likes the most about FPC: working with streams.

Besides that, in case the data is to be 'decoded' first, then the end-user is not allowed to just point to the memory location of the 'encoded' stream.

Therefor a function like uos_addFromMemory() will still not allow the end-user to use streams.

User would have to extract the data from the stream first, store it into memory and then offer it to this function (just as inefficient as the previous writeln exampe i showed).

btw: Yes, that might be an array of float (that is, in case the sound format expects to consist out of floats, otherwise it's another type).

The PM i sended Fred vS is a simple implementation of the virtual functions offered by libsndfile and uses FPC streams to load from and save to. libsndfile itself does not care where the data is actually coming from.

To Fred vS i would like to say:

UOS is your library and you are the maintainer. Either you would like to support FPC streams or not. No hard feelings either way.

The only thing i did is responding to TS question in which TS expressed his question if it was possible to load data from a Stream.

The virtual functions of libsndfile allows to do so. The only thing i do not know if UOS itself is able to make use of that (in theory it should be able to).

[Phoenix]

Hello @Fred vS,

function uos_AddFromMemory (PlayerIndex: cint32; MemoryBuffer: PDArFloat; OutputIndex: cint32;
   SampleFormat: cint32; SampleRate: cint32; Channels: cint32; FramesCount: cint32): cint32;

It did not accept as a parameter an TMemoryStream but will be useful.
I try to help by implementing a method for using sf_open_virtual that solves the problem.
This is my implementation: 

Code: Pascal  [Select]

1. Type
2.  PMemoryStream = ^TMemoryStream;
3.  sf_count_t = Int64;
4.  
5.  //pm_get_filelen = ^tm_get_filelen;
6.  tm_get_filelen =
7.   function (pms: PMemoryStream): sf_count_t;
8.  //pm_seek = ^tm_seek;
9.  tm_seek =
10.   function (offset: sf_count_t; whence: Integer; pms: PMemoryStream): sf_count_t;
11.  //pm_read = ^tm_read;
12.  tm_read =
13.   function (buf: Pointer; count: sf_count_t; pms: PMemoryStream): sf_count_t;
14.  //pm_write = ^tm_write;
15.  tm_write =
16.   function (const buf: Pointer; count: sf_count_t; pms: PMemoryStream): sf_count_t;
17.  //pm_tell = ^tm_tell;
18.  tm_tell =
19.   function (pms: PMemoryStream): sf_count_t;
20.  
21.  TSF_VIRTUAL = packed record
22.   sf_vio_get_filelen  : tm_get_filelen;
23.   sf_vio_seek         : tm_seek;
24.   sf_vio_read         : tm_read;
25.   sf_vio_write        : tm_write;
26.   sf_vio_tell         : tm_tell;
27.  end;
28.  
29. function m_get_filelen(pms: PMemoryStream): sf_count_t;
30. begin
31.  Result:= pms^.Size;
32. end;
33.  
34. function m_seek(offset: sf_count_t; whence: Integer; pms: PMemoryStream): sf_count_t;
35. Const
36.  SEEK_SET = 0;
37.  SEEK_CUR = 1;
38.  SEEK_END = 2;
39. begin
40.  case whence of
41.   SEEK_SET: Result:= pms^.Seek(offset, soFromBeginning);
42.   SEEK_CUR: Result:= pms^.Seek(offset, soFromCurrent);
43.   SEEK_END: Result:= pms^.Seek(offset, soFromEnd);
44.  end;
45. end;
46.  
47. function m_read(buf: Pointer; count: sf_count_t; pms: PMemoryStream): sf_count_t;
48. begin
49.  Result:= pms^.Read(buf^,count);
50. end;
51.  
52. function m_write(const buf: Pointer; count: sf_count_t; pms: PMemoryStream): sf_count_t;
53. begin
54.  Result:= pms^.Write(buf^,count);
55. end;
56.  
57. function m_tell(pms: PMemoryStream): sf_count_t;
58. begin
59.  Result:= pms^.Position;
60. end;
61.  
62. procedure TSSoundUOS.TestLibSndFile;
63. Var
64.  sfInfo: TSF_INFO;
65.  sfVirtual: TSF_VIRTUAL;
66.  
67.  procedure ShowInfo;
68.  Var
69.   sl: TStringList;
70.  begin
71.   sl:= TStringList.Create;
72.   try
73.    with sfInfo do
74.    begin
75.     sl.Add('frames: '+IntToStr(frames));
76.     sl.Add('samplerate: '+IntToStr(samplerate));
77.     sl.Add('channels: '+IntToStr(channels));
78.     sl.Add('format: '+IntToStr(format));
79.     sl.Add('sections: '+IntToStr(sections));
80.     sl.Add('seekable: '+IntToStr(seekable));
81.    end;
82.    ShowMessage(sl.Text);
83.   finally
84.    sl.Free;
85.   end;
86.  end;
87.  
88. Const
89.  path_test = 'c:\test.flac'; //for simulate
90. Var
91.  ms: TMemoryStream;
92. begin
93.  FillChar(sfInfo, SizeOf(sfinfo), 0);
94.  sf_open(path_test, SFM_READ, sfInfo);
95.  ShowInfo;
96.  
97.  with sfVirtual do
98.  begin
99.   sf_vio_get_filelen  := m_get_filelen;
100.   sf_vio_seek         := m_seek;
101.   sf_vio_read         := m_read;
102.   sf_vio_write        := m_write;
103.   sf_vio_tell         := m_tell;
104.  end;
105.  
106.  FillChar(sfInfo, SizeOf(sfinfo), 0);
107.  ms:= TMemoryStream.Create;
108.  try
109.   ms.LoadFromFile(path_test);
110.   ms.Position:= 0;
111.   sf_open_virtual(@sfVirtual, SFM_READ, @sfInfo, @ms);
112.   ShowInfo;
113.  finally
114.   ms.Free;
115.  end;
116. end;  
117.  

This work on Windows 10 64bit and Lazarus 1.6.2 FPC 3.0.0 64bit 

Now create this

function Tuos_Player.AddFromMStream(ms: TMemoryStream; OutputIndex: cint32;
  SampleFormat: cint32 ; FramesCount: cint32 ): cint32;

Replace the code that uses sf_open with sf_open_virtual

Code: Pascal  [Select]

1. Streamin [x] .Data.HandleSt: = sf_open (FileName, SFM_READ, sfinfo);
2.  
3. Streamin [x] .Data.HandleSt: = sf_open_virtual(@sfVirtual, SFM_READ, @sfInfo, @ms);
4.  

is it solve for libsndfile, you only have to test all 

[molly]

This is my implementation: 

Shame as that is (almost) exactly what i sended Fred Vs in my PM to him as well ;-)

Now create this

function Tuos_Player.AddFromMStream(ms: TMemoryStream; OutputIndex: cint32;
  SampleFormat: cint32 ; FramesCount: cint32 ): cint32;

Replace the code that uses sf_open with sf_open_virtual

Code: Pascal  [Select]

1. Streamin [x] .Data.HandleSt: = sf_open (FileName, SFM_READ, sfinfo);
2.  
3. Streamin [x] .Data.HandleSt: = sf_open_virtual(@sfVirtual, SFM_READ, @sfInfo, @ms);
4.  

is it solve for libsndfile, you only have to test all 

Would that indeed be enough for UOS to be able to add streaming support in a safe manner ?

[Fred vS]

If you want to use a memorystream, it is up to you.
But, AFAIK, a memorystream needs data.

Then, only use AddFromMemory(data_of_memorystream).

Why do you want to work with streams?
uos does the seek(), read() in the main loop.

In uos there is a utility: 

Code: Pascal  [Select]

1. bufferdata := FiletoMemory(filename);

Then store that bufferdata into ressource.

After this, you may use:
uos_AddFromMemory (bufferdata,...);

function uos_AddFromMemory (PlayerIndex: cint32; MemoryBuffer: PDArFloat; OutputIndex: cint32;
   SampleFormat: cint32; SampleRate: cint32; Channels: cint32; FramesCount: cint32): cint32;

It did not accept as a parameter an TMemoryStream but will be useful.

OK, I will add a demo in uos to show how to do 

Fre;D

[molly]

If you want to use a memorystream, it is up to you.

Meaning that you won't consider adding support for streams ?

A decision i personally can't understand at all nor have i seen any valid reason(s) to not support streams but, it is fine with me if that is to be the choice.

[Fred vS]

If you want to use a memorystream, it is up to you.

Meaning that you won't consider adding support for streams ?

What are you taking?
uos is full off streams.
OK, I will add a function with TMemoryStream as input.

Thanks for all.

Fre;D

[Phoenix]

Hello,

@molly
After all, we used the same sample in c as a starting point. 

I have tested the changes and indeed the sound works perfectly, but at the end of the sound crashes. Perhaps I created a bug or change is not enough. Even using PlayNoFree and without the Free TMemoryStream not solve.

Aspect of the implementation of Free vS but I was curious to try. 

@Fred vS
Thanks to the decision to add the method!! 

Thank you all!!

[Fred vS]

OK, I will add a demo in uos to show how to do 

Hello.

Added ConsolePlayMemory.pas in last commit  d35cb28..0746826 to show how to use memory buffer as input.
Note that with this added in ressource you will not need to load audio libraries anymore.

uos will do everything alone (only portaudio is needed).

Fre;D

[Phoenix]

Thanks for add 

[Phoenix]

The solution has been found !!! 
For those interested look
http://uos.2369694.n4.nabble.com/Load-sound-from-TMemoryStream-td28.html