On Thursday 2008-11-27 00:13, Nico Sabbi wrote: >> >The man page says: >> >> -dumpaudio (MPlayer only) >> >> Dumps raw compressed audio stream to ./stream.dump (useful with MPEG/AC-3, in most other >> >> cases the resulting file will not be playable). >> > >> >Where "not playable" does really mean "No way _anything_ can play that. >> >Really. Impossible." >> >> Oh really? Then why can the standalone programs mpg123 and faad2 >> decode/play it without any problems? > >if the is in ADTS format then mplayer can play it, too, (eventually >with -demuxer aac) but if the file is in raw format the configuration >bits are missing, thus not even faad can decode it. Reimar is right: >no one can. > >Run >$ file file.aac > >what's the output? Finding test cases where this triggers, here goes. Two different ones: MP3 and AAC. # # certain imeem.com streams with MP3 audio and no video # e.g. # http://www.imeem.com/groups/evHYCbeE/music/ei3FP_r2/chi_chi_ching_ft_bling_dawg_popcorn_pop_summer_2k8/ # $ mv /tmp/FlashDZK7MX t1.flv $ mplayer t1.flv Opening audio decoder: [mp3lib] MPEG layer-2, layer-3 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) (outputs sound) $ file t1-stream.dump stream.dump: MPEG ADTS, layer III, v1, 128 kbps, 44.1 kHz, JntStereo $ mplayer stream.dump MPEG-PES file format detected. MPEG: FATAL: EOF while searching for sequence header. Video: Cannot read properties. ========================================================================== Opening audio decoder: [mp3lib] MPEG layer-2, layer-3 ADecoder init failed :( ADecoder init failed :( Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders Unknown/missing audio format -> no sound (more) $ mpg123 stream.dump (outputs sound) # # youtube files with AAC audio # e.g. http://www.youtube.com/watch?v=T6KICpFueHg&feature=related&fmt=18 # $ mplayer t2.flv Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding) FAAD: compressed input bitrate missing, assuming 128kbit/s! AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 16000->176400) Selected audio codec: [faad] afm: faad (FAAD AAC (MPEG-2/MPEG-4 Audio) decoder) (outputs sound) $ file t2-stream.dump stream.dump: data $ faad -f2 -o- t2-stream.dump | aplay -f cd t2-stream.dump file info: LC AAC 180.405 secs, 2 ch, 44100 Hz (outputs sound)
