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diff --git a/mpeglib/lib/tplay/README b/mpeglib/lib/tplay/README new file mode 100644 index 00000000..275d6a9f --- /dev/null +++ b/mpeglib/lib/tplay/README @@ -0,0 +1,95 @@ +This is a buffered audio player for Linux. POSIX-thread library is +used. This is still considered BETA software and may not work as +expected. Please mail me for bug reports, opinions or suggestions. + +This is primarily made for use with MPEG-decoders. They typically +consume lots of CPU-time and some kind of audio buffer is needed to +reduce cutting while writing to audio device. You can also play any +audio files with tplay or use it with any program that writes audio +data to standard out. + +RIFF/WAVE (WAV) and Sun audio (AU) file headers are recognized by +now. + +Binary: + +In the source tree there is a readily compiled binary that is build +under Linux/ELF 2.0.30 with libc 5.4.20 and LinuxThreads 0.6 (the +thread library is statically linked). + +Command line options: + + tplay [-hvVmuxrf] [-s Hz] [-b 8|16] [-B kilobytes] [filename] + + -h, --help Print help, then exit + -v, --version Print version, then exit + -V, --verbose Print useful information about the sample + -x, --swap Swap endianness + -r, --raw Force raw audio format. Ignore headers. + -f, --force Force playing with any parameters + -m, --mono Mono sample + -u, --usage Print buffer usage while playing + -s, --speed=SPEED Sample speed (Hz) + -b, --bytes=BYTES Bytes in a sample + -B, --buffer-size=SIZE Buffer size in (kB) + +Buffer size is defaulted to 512k. It is about 3 seconds CD audio +(44100Hz/sample, 16bytes, stereo). If filename is not given, standard +input is used. If -x (or --swap) flag is set, the byte order of +audio sample is swapped before playing. The default is Intel little- +endian which is mostly used in x86 machines. The world outside Intel +is big-endian. +Option -r (or --raw) forces tplay to handle the sample as an raw +PCM audio sample. Sun audio or WAV headers are ignored. + +Requirements: + + - Linux 2.0 or newer with audio card support + - POSIX thread library + - Audio card + +There are several POSIX thread libraries available. I used +LinuxThreads by Xavier Leroy (Xavier.Leroy@inria.fr). LinuxThreads +library use clone() that is provided by Linux 2.0 kernel. + +The code: + +tplay starts one thread, named consumer, that reads circular audio +buffer and writes it to audio device. The producer is a function that +runs in parallel with the consumer and its task is to read the sample +file or standard input and write this data to audio buffer to meet +consumer's needs. Usually, the buffer is full but on the times when +CPU-time is suddenly needed for other processes (usually: disk +read/write), the producer can't write fast enough and consumer can use +the buffer to keep audio stream uninterrupted. If the buffer is used +and the producer is still unable to feed it fast enough, underflow +situation is met and consumer waits for awhile (typically: one second) +for the producer to fill the buffer again. + +Building: + +If you want to link tplay with static libpthread library, edit +Makefile and uncomment preferred LIBS-setting there. Type: + + - make + - make install + - make install.man + +Thanks: + +Jerko Golubovic <jerko.golubovic@public.srce.hr> +Jukka Palviainen <oh3kjt@ele.tut.fi> + +TODO: + +Find out the best sizes for the audio buffer and one block. +Better documentation. +Better RIFF/WAVE checking. + +Ilkka Karvinen +ik@iki.fi + + + + + |