[SOLVED] mp3 decoding with noise

Massimiliano Cialdi

Expert 1995 points

Other Parts Discussed in Thread: OMAP-L138, OMAPL138

I have OMAP-L138 and use DVSDK 04.03.00.06. I have integrated the mp3 decoder (v. 1.31.01.001) following the wiki page 'How do I Integrate new codecs into DVSDK'.

I have also modified gstticodecs_omapl138.c, in ti-dvsdk_omapl138-evm_04_03_00_06/gstreamer-ti_svnr919/src/ directory, to add mp3 support to gstreamer:

    {
        "MPEG1L3 Audio Decoder",     /* String name of codec used by plugin      */
        "mp3dec",              /* String name of codec used by CE          */
        codecServer              /* Engine that contains this codec          */
    },
    {
        "MPEG1L2 Audio Decoder",     /* String name of codec used by plugin      */
        "mp3dec",              /* String name of codec used by CE          */
        codecServer              /* Engine that contains this codec          */
    },

It works using gst-launch:

gst-launch filesrc location=davinci.mp3 num-buffers=20 ! typefind ! TIAuddec1 ! alsasink -v

(the file davinci.mp3 is provided as a test with mp3 decoder)

The process goes on without errors, but you hear a noise. I have redirected the output to a wav file in this way:

gst-launch filesrc location=davinci.mp3 num-buffers=20 ! typefind ! TIAuddec1 ! wavenc ! filesink location=davinci.wav -v

so you can download and hear it. The file is https://webmail.powersoft.it/download/davinci.wav

Is it a bug of the decoder?

How can I avoid this noise?

best regards

over 12 years ago

0 Yashwant Dutt over 12 years ago

TI__Genius 17215 points

The mp3 codec release package will also have a stansalone test application, you can check if the issue is with decoder or not there. Generally, I dont think the issue would be be the decoder, it would be something related to the system. If possible, try to tap the pcm sample going into the codec for a small duration and try checking if the input itself has that noise or not.

regards

Yashwant

0 Massimiliano Cialdi over 12 years ago in reply to Yashwant Dutt

Expert 1995 points

I'd try the stand alone application but I can not compile. I have CCS5.3 running on linux.

How can I compile the stand alone application?

best regards

0 Massimiliano Cialdi over 12 years ago in reply to Yashwant Dutt

Expert 1995 points

SOLVED.

It is about how server is built.

Starting from this post, I supposed that the right skeleton interface is MP3DEC_INBUFCACHEFLUSH and MP3DEC_TII_IMP3DEC. It was so tricky to build a codec server with MP3 decoder using these functions but once built you can not hear noise any more.

best regards

Processors

Processors forum

[SOLVED] mp3 decoding with noise