Hi First time posting.
I'm currently using liquidsoap to transcode a live MP3 stream to a lower bitrate AAC+ stream. However the AAC+ stream is not suitable because it is VBR and we require CBR. There appears to be no way to set CBR within liquidsoap. The input MP3 stream is CBR. I am therefore now trying to accomplish this with ffmpeg. I am running Debian version 7.8 and ffmpeg version below: ffmpeg version 1.0.10 Copyright (c) 2000-2014 the FFmpeg developers built on Jul 25 2014 07:50:40 with gcc 4.7 (Debian 4.7.2-5) configuration: --prefix=/usr --extra-cflags='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security ' --extra-ldflags='-Wl,-z,relro' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-libfdk-aac --enable-libdc1394 --disable-altivec --dis libavutil 51. 73.101 / 51. 73.101 libavcodec 54. 59.100 / 54. 59.100 libavformat 54. 29.104 / 54. 29.104 libavdevice 54. 2.101 / 54. 2.101 libavfilter 3. 17.100 / 3. 17.100 libswscale 2. 1.101 / 2. 1.101 libswresample 0. 15.100 / 0. 15.100 libpostproc 52. 0.100 / 52. 0.100 I have tried various combinations of commands and I think this gets me closest - stream details amended to protect the guilty: /usr/bin/ffmpeg -re -user-agent 42 -i http://example1.com:8002/stream.mp3 -c:a libfaac -ar 44100 -ab 48k -acodec copy http://username:[email protected]:8099/stream.aac -v debug The output of the above gives me the following: user@machine:~# /usr/bin/ffmpeg -re -user-agent 42 -i http://example1.com:8002/stream.mp3 -c:a libfaac -ar 44100 -ab 48k -acodec copy http://username:[email protected]:8099/stream.aac -v debug ffmpeg version 1.0.10 Copyright (c) 2000-2014 the FFmpeg developers built on Jul 25 2014 07:50:40 with gcc 4.7 (Debian 4.7.2-5) configuration: --prefix=/usr --extra-cflags='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security ' --extra-ldflags='-Wl,-z,relro' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-libfdk-aac --enable-libdc1394 --disable-altivec --dis libavutil 51. 73.101 / 51. 73.101 libavcodec 54. 59.100 / 54. 59.100 libavformat 54. 29.104 / 54. 29.104 libavdevice 54. 2.101 / 54. 2.101 libavfilter 3. 17.100 / 3. 17.100 libswscale 2. 1.101 / 2. 1.101 libswresample 0. 15.100 / 0. 15.100 libpostproc 52. 0.100 / 52. 0.100 [mp3 @ 0x134ee20] Format mp3 probed with size=131072 and score=50 [mp3 @ 0x134ee20] File position before avformat_find_stream_info() is 0 [mp3 @ 0x1358720] Header missing [mp3 @ 0x134ee20] max_analyze_duration 5000000 reached at 5015510 [mp3 @ 0x134ee20] Estimating duration from bitrate, this may be inaccurate [mp3 @ 0x134ee20] File position after avformat_find_stream_info() is 81920 Input #0, mp3, from 'http://example1.com:8002/stream.mp3': Duration: N/A, start: 0.000000, bitrate: 128 kb/s Stream #0:0, 194, 1/14112000: Audio: mp3, 44100 Hz, stereo, s16, 128 kb/s Output #0, adts, to 'http://username:[email protected]:8099/stream.aac -v debug': Metadata: encoder : Lavf54.29.104 Stream #0:0, 0, 1/90000: Audio: mp3, 44100 Hz, stereo, 128 kb/s Stream mapping: Stream #0:0 -> #0:0 (copy) Press [q] to stop, [?] for help But no ffmpeg process is running and consequently no transcoded stream is available. Any suggestions. All help gratefully received. Best regards Chip Scooter _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
