lamemp3enc

lamemp3enc — High-quality free MP3 encoder

Synopsis

                    GstLameMP3Enc;

Object Hierarchy

  GObject
   +----GstObject
         +----GstElement
               +----GstLameMP3Enc

Implemented Interfaces

GstLameMP3Enc implements GstPreset.

Properties

  "bitrate"                  gint                  : Read / Write
  "cbr"                      gboolean              : Read / Write
  "encoding-engine-quality"  GstLameMP3EncEncodingEngineQuality  : Read / Write
  "mono"                     gboolean              : Read / Write
  "quality"                  gfloat                : Read / Write
  "target"                   GstLameMP3EncTarget   : Read / Write

Description

This element encodes raw integer audio into an MPEG-1 layer 3 (MP3) stream. Note that MP3 is not a free format, there are licensing and patent issues to take into consideration. See Ogg/Vorbis for a royalty free (and often higher quality) alternative.

Output sample rate

If no fixed output sample rate is negotiated on the element's src pad, the element will choose an optimal sample rate to resample to internally. For example, a 16-bit 44.1 KHz mono audio stream encoded at 48 kbit will get resampled to 32 KHz. Use filter caps on the src pad to force a particular sample rate.

Example pipelines

1
gst-launch -v audiotestsrc wave=sine num-buffers=100 ! audioconvert ! lamemp3enc ! filesink location=sine.mp3
Encode a test sine signal to MP3.
1
gst-launch -v alsasrc ! audioconvert ! lamemp3enc target=bitrate bitrate=192 ! filesink location=alsasrc.mp3
Record from a sound card using ALSA and encode to MP3 with an average bitrate of 192kbps
1
gst-launch -v filesrc location=music.wav ! decodebin ! audioconvert ! audioresample ! lamemp3enc target=quality quality=0 ! id3v2mux ! filesink location=music.mp3
Transcode from a .wav file to MP3 (the id3v2mux element is optional) with best VBR quality
1
gst-launch -v cdda://5 ! audioconvert ! lamemp3enc target=bitrate cbr=true bitrate=192 ! filesink location=track5.mp3
Encode Audio CD track 5 to MP3 with a constant bitrate of 192kbps
1
gst-launch -v audiotestsrc num-buffers=10 ! audio/x-raw-int,rate=44100,channels=1 ! lamemp3enc target=bitrate cbr=true bitrate=48 ! filesink location=test.mp3
Encode to a fixed sample rate

Details

GstLameMP3Enc

typedef struct _GstLameMP3Enc GstLameMP3Enc;

Opaque data structure.

Property Details

The "bitrate" property

  "bitrate"                  gint                  : Read / Write

Bitrate in kbit/sec (Only valid if target is bitrate, for CBR one of 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 or 320).

Allowed values: [8,320]

Default value: 128


The "cbr" property

  "cbr"                      gboolean              : Read / Write

Enforce constant bitrate encoding (Only valid if target is bitrate).

Default value: FALSE


The "encoding-engine-quality" property

  "encoding-engine-quality"  GstLameMP3EncEncodingEngineQuality  : Read / Write

Quality/speed of the encoding engine, this does not affect the bitrate!.

Default value: Standard


The "mono" property

  "mono"                     gboolean              : Read / Write

Enforce mono encoding.

Default value: FALSE


The "quality" property

  "quality"                  gfloat                : Read / Write

VBR Quality from 0 to 10, 0 being the best (Only valid if target is quality).

Allowed values: [0,9.999]

Default value: 4


The "target" property

  "target"                   GstLameMP3EncTarget   : Read / Write

Optimize for quality or bitrate.

Default value: Quality

See Also

lame, mad, vorbisenc