LD_LIBRARY_PATH=./ ./ffmpeg -loglevel 60 -f alsa -ac 1 -i 'front:CARD=C615,DEV=0' -filter_complex '[0:0] [d] libspeex_aec, asplit [acpl] [pl]; aevalsrc=s=48000:d=2134:c=mono:exprs=0, aformat=sample_fmts=s16p [fd]; [fd] [acpl] concat=v=0:a=1 [d];[pl] aformat=channel_layouts=mono [plr]; anullsrc=mono:48000 [i2];[i2] [plr] amerge=2 [c2]' -map '[c2]' -f alsa 'front:CARD=PCH,DEV=0' >log.txt 2>&1 ffmpeg version N-91595-g390d7ea2a3 Copyright (c) 2000-2018 the FFmpeg developers built with gcc 8.2.0 (GCC) configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --disable-everything --enable-gpl --enable-encoder=opus --enable-encoder=png --enable-encoder=pcm_s16le --enable-encoder=libx264 --enable-decoder=opus --enable-decoder=png --enable-decoder=h264 --enable-decoder=mjpeg --enable-decoder=pcm_s16le --enable-decoder=aac --enable-muxer=matroska --enable-muxer=mov --enable-muxer=rtp --enable-muxer=rtsp --enable-demuxer=matroska --enable-demuxer=sdp --enable-demuxer=rtp --enable-demuxer=rtsp --enable-parser=opus --enable-parser=h264 --enable-parser=png --enable-protocol=udp --enable-protocol=tcp --enable-protocol=rtp --enable-protocol=file --enable-protocol=http --enable-indev=alsa --enable-indev=v4l2 --enable-outdev=alsa --enable-outdev=fbdev --enable-outdev=sdl2 --enable-filter=scale --enable-filter=adelay --enable-filter=afifo --enable-filter=aresample --enable-filter=asplit --enable-filter=resample --enable-filter=anullsrc --enable-filter=aevalsrc --enable-filter=amix --enable-filter=amerge --enable-filter=channelsplit --enable-filter=volume --enable-filter=volumedetect --enable-filter=crop --enable-filter=eq --enable-filter=format --enable-filter=lenscorrection --enable-filter=libspeex_aec --enable-filter=vignette --enable-filter=perspective --enable-filter=concat --enable-filter=split --enable-libdrm --enable-libopus --enable-libpulse --enable-libspeexdsp --enable-libv4l2 --enable-libx264 --enable-libxml2 --enable-shared --enable-version3 --disable-ffprobe --disable-doc --enable-debug=2 --disable-optimizations libavutil 56. 19.100 / 56. 19.100 libavcodec 58. 22.101 / 58. 22.101 libavformat 58. 17.101 / 58. 17.101 libavdevice 58. 4.101 / 58. 4.101 libavfilter 7. 26.100 / 7. 26.100 libswscale 5. 2.100 / 5. 2.100 libswresample 3. 2.100 / 3. 2.100 libpostproc 55. 2.100 / 55. 2.100 Splitting the commandline. Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '60'. Reading option '-f' ... matched as option 'f' (force format) with argument 'alsa'. Reading option '-ac' ... matched as option 'ac' (set number of audio channels) with argument '1'. Reading option '-i' ... matched as input url with argument 'front:CARD=C615,DEV=0'. Reading option '-filter_complex' ... matched as option 'filter_complex' (create a complex filtergraph) with argument '[0:0] [d] libspeex_aec, asplit [acpl] [pl]; aevalsrc=s=48000:d=2134:c=mono:exprs=0, aformat=sample_fmts=s16p [fd]; [fd] [acpl] concat=v=0:a=1 [d];[pl] aformat=channel_layouts=mono [plr]; anullsrc=mono:48000 [i2];[i2] [plr] amerge=2 [c2]'. Reading option '-map' ... matched as option 'map' (set input stream mapping) with argument '[c2]'. Reading option '-f' ... matched as option 'f' (force format) with argument 'alsa'. Reading option 'front:CARD=PCH,DEV=0' ... matched as output url. Finished splitting the commandline. Parsing a group of options: global . Applying option loglevel (set logging level) with argument 60. Applying option filter_complex (create a complex filtergraph) with argument [0:0] [d] libspeex_aec, asplit [acpl] [pl]; aevalsrc=s=48000:d=2134:c=mono:exprs=0, aformat=sample_fmts=s16p [fd]; [fd] [acpl] concat=v=0:a=1 [d];[pl] aformat=channel_layouts=mono [plr]; anullsrc=mono:48000 [i2];[i2] [plr] amerge=2 [c2]. Successfully parsed a group of options. Parsing a group of options: input url front:CARD=C615,DEV=0. Applying option f (force format) with argument alsa. Applying option ac (set number of audio channels) with argument 1. Successfully parsed a group of options. Opening an input file: front:CARD=C615,DEV=0. [alsa @ 0x56554d3328c0] All info found [alsa @ 0x56554d3328c0] stream 0: start_time: 1536038679.812 duration: -9223372036854.775 [alsa @ 0x56554d3328c0] format: start_time: 1536038679.812 duration: -9223372036854.775 bitrate=768 kb/s Guessed Channel Layout for Input Stream #0.0 : mono Input #0, alsa, from 'front:CARD=C615,DEV=0': Duration: N/A, start: 1536038679.812124, bitrate: 768 kb/s Stream #0:0, 1, 1/1000000: Audio: pcm_s16le, 48000 Hz, mono, s16, 768 kb/s Successfully opened the file. [Parsed_aevalsrc_2 @ 0x56554d383c40] Setting 's' to value '48000' [Parsed_aevalsrc_2 @ 0x56554d383c40] Setting 'd' to value '2134' [Parsed_aevalsrc_2 @ 0x56554d383c40] Setting 'c' to value 'mono' [Parsed_aevalsrc_2 @ 0x56554d383c40] Setting 'exprs' to value '0' [Parsed_aformat_3 @ 0x56554d384ac0] Setting 'sample_fmts' to value 's16p' [Parsed_concat_4 @ 0x56554d3859c0] Setting 'v' to value '0' [Parsed_concat_4 @ 0x56554d3859c0] Setting 'a' to value '1' [Parsed_aformat_5 @ 0x56554d386300] Setting 'channel_layouts' to value 'mono' [Parsed_anullsrc_6 @ 0x56554d387f40] Setting 'channel_layout' to value 'mono' [Parsed_anullsrc_6 @ 0x56554d387f40] Setting 'sample_rate' to value '48000' [Parsed_amerge_7 @ 0x56554d388880] Setting 'inputs' to value '2' Parsing a group of options: output url front:CARD=PCH,DEV=0. Applying option map (set input stream mapping) with argument [c2]. Applying option f (force format) with argument alsa. Successfully parsed a group of options. Opening an output file: front:CARD=PCH,DEV=0. Successfully opened the file. Stream mapping: Stream #0:0 (pcm_s16le) -> libspeex_aec:record amerge -> Stream #0:0 (pcm_s16le) Press [q] to stop, [?] for help cur_dts is invalid (this is harmless if it occurs once at the start per stream) detected 4 logical cores [Parsed_aevalsrc_2 @ 0x56554d38c800] Setting 's' to value '48000' [Parsed_aevalsrc_2 @ 0x56554d38c800] Setting 'd' to value '2134' [Parsed_aevalsrc_2 @ 0x56554d38c800] Setting 'c' to value 'mono' [Parsed_aevalsrc_2 @ 0x56554d38c800] Setting 'exprs' to value '0' [Parsed_aformat_3 @ 0x56554d38d680] Setting 'sample_fmts' to value 's16p' [Parsed_concat_4 @ 0x56554d386080] Setting 'v' to value '0' [Parsed_concat_4 @ 0x56554d386080] Setting 'a' to value '1' [Parsed_aformat_5 @ 0x56554d38b940] Setting 'channel_layouts' to value 'mono' [Parsed_anullsrc_6 @ 0x56554d389900] Setting 'channel_layout' to value 'mono' [Parsed_anullsrc_6 @ 0x56554d389900] Setting 'sample_rate' to value '48000' [Parsed_amerge_7 @ 0x56554d38c400] Setting 'inputs' to value '2' [graph_0_in_0_0 @ 0x56554d38ecc0] Setting 'time_base' to value '1/48000' [graph_0_in_0_0 @ 0x56554d38ecc0] Setting 'sample_rate' to value '48000' [graph_0_in_0_0 @ 0x56554d38ecc0] Setting 'sample_fmt' to value 's16' [graph_0_in_0_0 @ 0x56554d38ecc0] Setting 'channel_layout' to value '0x4' [graph_0_in_0_0 @ 0x56554d38ecc0] tb:1/48000 samplefmt:s16 samplerate:48000 chlayout:0x4 [format_out_0_0 @ 0x56554d38d580] Setting 'sample_fmts' to value 's16' [Parsed_libspeex_aec_0 @ 0x56554d38b480] auto-inserting filter 'auto_fifo_0' between the filter 'graph_0_in_0_0' and the filter 'Parsed_libspeex_aec_0' [Parsed_libspeex_aec_0 @ 0x56554d38b480] auto-inserting filter 'auto_fifo_1' between the filter 'Parsed_concat_4' and the filter 'Parsed_libspeex_aec_0' [Parsed_amerge_7 @ 0x56554d38c400] Input channel layouts overlap: output layout will be determined by the number of distinct input channels [Parsed_aformat_3 @ 0x56554d38d680] auto-inserting filter 'auto_resampler_0' between the filter 'Parsed_aevalsrc_2' and the filter 'Parsed_aformat_3' [Parsed_amerge_7 @ 0x56554d38c400] auto-inserting filter 'auto_resampler_1' between the filter 'Parsed_aformat_5' and the filter 'Parsed_amerge_7' [auto_fifo_0 @ 0x56554d384ec0] auto-inserting filter 'auto_resampler_2' between the filter 'graph_0_in_0_0' and the filter 'auto_fifo_0' [AVFilterGraph @ 0x56554d38a600] query_formats: 13 queried, 28 merged, 11 already done, 0 delayed [Parsed_anullsrc_6 @ 0x56554d389900] sample_rate:48000 channel_layout:'mono' nb_samples:1024 [auto_resampler_2 @ 0x56554d392cc0] [SWR @ 0x56554d3bf600] Using s16p internally between filters [auto_resampler_2 @ 0x56554d392cc0] ch:1 chl:mono fmt:s16 r:48000Hz -> ch:1 chl:mono fmt:s16p r:48000Hz [Parsed_aevalsrc_2 @ 0x56554d38c800] sample_rate:48000 chlayout:mono duration:2134000000 [auto_resampler_0 @ 0x56554d38d380] [SWR @ 0x56554d394e80] Using dblp internally between filters [auto_resampler_0 @ 0x56554d38d380] ch:1 chl:mono fmt:dblp r:48000Hz -> ch:1 chl:mono fmt:s16p r:48000Hz [Parsed_asplit_1 @ 0x56554d38bb80] circular filter chain detected [Parsed_libspeex_aec_0 @ 0x56554d38b480] mics:1 speakers:1 [auto_resampler_1 @ 0x56554d3aa1c0] [SWR @ 0x56554d3aa640] Using s16p internally between filters [auto_resampler_1 @ 0x56554d3aa1c0] ch:1 chl:mono fmt:s16p r:48000Hz -> ch:1 chl:mono fmt:s16 r:48000Hz [Parsed_amerge_7 @ 0x56554d38c400] in0:mono + in1:mono -> out:stereo Output #0, alsa, to 'front:CARD=PCH,DEV=0': Metadata: encoder : Lavf58.17.101 Stream #0:0, 0, 1/48000: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s Metadata: encoder : Lavc58.22.101 pcm_s16le cur_dts is invalid (this is harmless if it occurs once at the start per stream) Last message repeated 12 times [alsa @ 0x56554d388bc0] ALSA buffer xrun. Last message repeated 21 times size=N/A time=00:00:00.49 bitrate=N/A speed=0.972x [alsa @ 0x56554d388bc0] ALSA buffer xrun. Last message repeated 22 times size=N/A time=00:00:00.98 bitrate=N/A speed=0.976x [alsa @ 0x56554d388bc0] ALSA buffer xrun. Last message repeated 17 times size=N/A time=00:00:01.36 bitrate=N/A speed=0.939x video:0kB audio:256kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown Input file #0 (front:CARD=C615,DEV=0): Input stream #0:0 (audio): 604 packets read (132576 bytes); 604 frames decoded (66288 samples); Total: 604 packets (132576 bytes) demuxed Output file #0 (front:CARD=PCH,DEV=0): Output stream #0:0 (audio): 64 frames encoded (65536 samples); 64 packets muxed (262144 bytes); Total: 64 packets (262144 bytes) muxed 604 frames successfully decoded, 0 decoding errors Exiting normally, received signal 2.