Hello, To continue my story, please let me say that I have successfully compiled Mplayer after removing completely FFmpeg from my system. However, the original problem, that is, the decoding of MP3 files is still there. I have used a 64bit version of mgp123 to play some MP3 file and there is absolutely no problem: $ /opt/gnu/bin/amd64/mpg123 -v song.mp3 High Performance MPEG 1.0/2.0/2.5 Audio Player for Layers 1, 2 and 3 version 20091026000000; written and copyright by Michael Hipp and others free software (LGPL/GPL) without any warranty but with best wishes Decoder: x86-64 (SSE) <------------------------------------------------------------------------------------------ Playing MPEG stream 1 of 1: song ... Title: Without you Artist: Some Artist Comment: Album: Year: Genre: Blues MPEG 1.0, Layer: III, Freq: 44100, mode: Joint-Stereo, modext: 0, BPF : 417 Channels: 2, copyright: No, original: Yes, CRC: No, emphasis: 0. Bitrate: 128 kbit/s Extension value: 0 Frame# 1206 [ 6353], Time: 00:31.50 [02:45.95], RVA: off, Vol: 100(100)^C [0:31] Decoding of Without you (Nilson).mp3 finished. Now when I play the same file with the 64bit version of mplayer, this what mplayer reports: ========================================================================== Opening audio decoder: [mp3lib] MPEG layer-2, layer-3 dec_audio: Allocating 4608 + 65536 = 70144 bytes for output buffer. mp3lib: using generic C decore! <-------------------------------------------------------------------------------------------------- MP3lib: init layer2&3 finished, tables done MPEG 1.0, Layer III, 44100 Hz 128 kbit Joint-Stereo, BPF: 417 Channels: 2, copyright: No, original: Yes, CRC: No, emphasis: 0 AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 16000->176400) Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3) ========================================================================== while the 32bit version reports the following: ========================================================================== Opening audio decoder: [mp3lib] MPEG layer-2, layer-3 dec_audio: Allocating 4608 + 65536 = 70144 bytes for output buffer. mp3lib: using 3DNow!Ex optimized decore! <---------------------------------------------------------------------------------- MP3lib: init layer2&3 finished, tables done MPEG 1.0, Layer III, 44100 Hz 128 kbit Joint-Stereo, BPF: 417 Channels: 2, copyright: No, original: Yes, CRC: No, emphasis: 0 AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 16000->176400) Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3) ========================================================================== So it seems the decore is not the appropriate one. Comments, suggestions? Regards, Apostolos Syropoulos