MPEG Audio Player
/usr/photon/bin/mpegaudio (Photon)
/lib/dll/mpegaudio_noph.so
The MPEG Audio player plugins are based on the Xing DVD Player and decode MPEG Audio Layers I, II and III (MP3).
They also support MPEG-2 low-bit rate streams and MPEG-2.5 Audio.
An attempt is made to skip past the wrappers that sometimes accompany MP3 files.
The mpegaudio_noph.so player is launched by typing
plaympegaudio_noph
at the command line.
Calling
MvInit()
sets the value of MvPluginCtrl_t.MvPluginFlags_t pflags to 0.
See the
Resource Profile Estimates and Library Dependencies appendix.
Valid commands for the MPEG audio player are:
CMD_PLUGIN_CLOSE
CMD_PLUGIN_DIRECT_AUDIO
CMD_PLUGIN_GET_STATUS
CMD_PLUGIN_MUTE
CMD_PLUGIN_OPEN_URLS
CMD_PLUGIN_PAUSE
CMD_PLUGIN_SEEK_TO
CMD_PLUGIN_SET_PARAMETER
CMD_PLUGIN_START
CMD_PLUGIN_STOP
- MPEGAUDIOBUFFERSIZE
- Size of the input buffer (default is 50000 bytes).
- MPEGAUDIOBUFFERSTARTPERCENT
- The percent of the input buffer that needs to be filled before you begin playing (default is 30).
- MPEGAUDIOCONVERTCODE
- Transform the output of the MPEG audio decoder.
- 0
- Two channel output (default).
- 1
- Convert two channel output to mono.
- 2
- Convert two channel output to left channel.
- 3
- Convert two channel output to right channel.
- MPEGAUDIOFREQLIMIT
- Set a low pass filter on the specified frequency.
Default is 24KHz. Maximum is 48KHz.
- MPEGAUDIOMAXBITRATE
- Set to value in Kbits-per-second.
The plugin automatically sets the reduction code value to ensure the decoded data rate is kept below
this specified value.
For example, the following sets the reduction code to 1 for a 128Kbps MPEG audio stream.
export MPEGAUDIOMAXBITRATE=65
 |
MPEG-1 and MPEG-2 audio bitstreams can encode at 8 to 480Kbps.
Divide this in half for MPEG-2.5 extended-streams.
|
- MPEGAUDIOREDUCTIONCODE
- Tells the plugin to down-sample the MPEG audio stream by a given factor to reduce the CPU load.
- 0
- Full sample rate output (default).
- 1
- Half rate.
- 2
- Quarter rate.
- MPEGAUDIOREFILLONUNDERFLOW
- Refill the audio input buffer to percent on underflow (default is OFF).
- MPEGAUDIOTRANSFORMBITCODE
- Transform the output of MPEG audio decoder.
- 0
- Perform no transformation.
- 1
- 16-bit linear PCM.
- 2
- 8-bit unsigned linear PCM.
- 3
- U-law (8-bit signed).
- MPEGAUDIOTRANSFORMCHANNELCODE
- Transform the output of the MPEG audio decoder.
- 0
- Two channel output (default).
- 1
- Convert two channel output to mono.
- 2
- Convert two channel output to left channel.
- 3
- Convert two channel output to right channel.
See the callback handler example in the
Soundfile player plugin
and the
plaympegaudio_noph.c
example in the Appendix.