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96 lines
3.1 KiB
96 lines
3.1 KiB
15 years ago
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This is a buffered audio player for Linux. POSIX-thread library is
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used. This is still considered BETA software and may not work as
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expected. Please mail me for bug reports, opinions or suggestions.
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This is primarily made for use with MPEG-decoders. They typically
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consume lots of CPU-time and some kind of audio buffer is needed to
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reduce cutting while writing to audio device. You can also play any
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audio files with tplay or use it with any program that writes audio
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data to standard out.
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RIFF/WAVE (WAV) and Sun audio (AU) file headers are recognized by
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now.
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Binary:
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In the source tree there is a readily compiled binary that is build
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under Linux/ELF 2.0.30 with libc 5.4.20 and LinuxThreads 0.6 (the
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thread library is statically linked).
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Command line options:
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tplay [-hvVmuxrf] [-s Hz] [-b 8|16] [-B kilobytes] [filename]
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-h, --help Print help, then exit
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-v, --version Print version, then exit
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-V, --verbose Print useful information about the sample
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-x, --swap Swap endianness
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-r, --raw Force raw audio format. Ignore headers.
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-f, --force Force playing with any parameters
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-m, --mono Mono sample
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-u, --usage Print buffer usage while playing
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-s, --speed=SPEED Sample speed (Hz)
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-b, --bytes=BYTES Bytes in a sample
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-B, --buffer-size=SIZE Buffer size in (kB)
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Buffer size is defaulted to 512k. It is about 3 seconds CD audio
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(44100Hz/sample, 16bytes, stereo). If filename is not given, standard
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input is used. If -x (or --swap) flag is set, the byte order of
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audio sample is swapped before playing. The default is Intel little-
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endian which is mostly used in x86 machines. The world outside Intel
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is big-endian.
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Option -r (or --raw) forces tplay to handle the sample as an raw
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PCM audio sample. Sun audio or WAV headers are ignored.
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Requirements:
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- Linux 2.0 or newer with audio card support
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- POSIX thread library
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- Audio card
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There are several POSIX thread libraries available. I used
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LinuxThreads by Xavier Leroy (Xavier.Leroy@inria.fr). LinuxThreads
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library use clone() that is provided by Linux 2.0 kernel.
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The code:
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tplay starts one thread, named consumer, that reads circular audio
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buffer and writes it to audio device. The producer is a function that
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runs in parallel with the consumer and its task is to read the sample
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file or standard input and write this data to audio buffer to meet
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consumer's needs. Usually, the buffer is full but on the times when
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CPU-time is suddenly needed for other processes (usually: disk
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read/write), the producer can't write fast enough and consumer can use
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the buffer to keep audio stream uninterrupted. If the buffer is used
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and the producer is still unable to feed it fast enough, underflow
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situation is met and consumer waits for awhile (typically: one second)
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for the producer to fill the buffer again.
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Building:
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If you want to link tplay with static libpthread library, edit
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Makefile and uncomment preferred LIBS-setting there. Type:
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- make
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- make install
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- make install.man
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Thanks:
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Jerko Golubovic <jerko.golubovic@public.srce.hr>
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Jukka Palviainen <oh3kjt@ele.tut.fi>
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TODO:
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Find out the best sizes for the audio buffer and one block.
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Better documentation.
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Better RIFF/WAVE checking.
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Ilkka Karvinen
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ik@iki.fi
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