I am very sorry - Outlook Web App sent the email when I tried to copy paste the command - also it won't let me bottom post! i promise that future emails will be in the correct format.
This is the command I used to do a one second test where the intention is to merge two mono audio tracks into one stereo track - i was hoping that there was a way to do this without a filter but i guess not?: ffmpeg -i "input.mov" -filter_complex " [0:2][0:3]join=inputs=2:channel_layout=stereo[a]" -map "[a]" -c:a pcm_s24le -c: v copy -t 1 output.mov ffmpeg version N-92623-g2c64a6bcd2 Copyright (c) 2000-2018 the FFmpeg developers built with gcc 8.2.1 (Rev1, Built by MSYS2 project) 20181130 configuration: --disable-autodetect --enable-amf --enable-bzlib --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-iconv --enable-lzma --e nable-nvenc --enable-zlib --enable-sdl2 --disable-debug --enable-ffnvcodec --ena ble-nvdec --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvp x --enable-libx264 --enable-libx265 --enable-libdav1d --enable-fontconfig --enab le-libass --enable-libbluray --enable-libfreetype --enable-libmfx --enable-libmy sofa --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enabl e-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libwavpack --e nable-libwebp --enable-libxml2 --enable-libzimg --enable-libshine --enable-gpl - -enable-avisynth --enable-libxvid --enable-libaom --enable-version3 --enable-chr omaprint --enable-decklink --enable-frei0r --enable-libbs2b --enable-libcaca --e nable-libcdio --enable-libfdk-aac --enable-libflite --enable-libfribidi --enable -libgme --enable-libgsm --enable-libilbc --enable-libkvazaar --enable-libmodplug --enable-libopenh264 --enable-libopenmpt --enable-librtmp --enable-librubberban d --enable-libssh --enable-libtesseract --enable-libxavs --enable-libzmq --enabl e-libzvbi --enable-opencl --enable-opengl --enable-libvmaf --enable-libcodec2 -- enable-libsrt --enable-ladspa --enable-openssl --extra-cflags=-fopenmp --extra-l ibs=-lgomp --extra-cflags=-DLIBTWOLAME_STATIC --extra-libs=-lstdc++ --extra-cfla gs=-DLIBSSH_STATIC --extra-ldflags='-Wl,--allow-multiple-definition' --extra-cfl ags=-DCACA_STATIC --extra-cflags=-DMODPLUG_STATIC --extra-cflags=-DCHROMAPRINT_N ODLL --extra-libs=-lstdc++ --extra-cflags=-DZMQ_STATIC --extra-libs=-lpsapi --ex tra-cflags=-DLIBXML_STATIC --extra-libs=-liconv --disable-w32threads --extra-cfl ags=-DKVZ_STATIC_LIB --enable-nonfree libavutil 56. 24.101 / 56. 24.101 libavcodec 58. 41.101 / 58. 41.101 libavformat 58. 23.102 / 58. 23.102 libavdevice 58. 6.101 / 58. 6.101 libavfilter 7. 46.101 / 7. 46.101 libswscale 5. 4.100 / 5. 4.100 libswresample 3. 4.100 / 3. 4.100 libpostproc 55. 4.100 / 55. 4.100 Guessed Channel Layout for Input Stream #0.2 : mono Guessed Channel Layout for Input Stream #0.3 : mono Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mov': Metadata: creation_time : 2019-09-18T09:27:36.000000Z Duration: 01:37:57.56, start: 0.000000, bitrate: 223490 kb/s Stream #0:0(eng): Video: v210 (v210 / 0x30313276), yuv422p10le(smpte170m/bt4 70bg/bt709, top coded first (swapped)), 720x576, 221184 kb/s, SAR 16:15 DAR 4:3, 25 fps, 25 tbr, 25k tbn, 25k tbc (default) Metadata: creation_time : 2019-09-18T09:27:36.000000Z handler_name : Apple Video Media Handler encoder : 10 bit YCbCr timecode : 00:58:04:15 Stream #0:1(eng): Data: none (tmcd / 0x64636D74) (default) Metadata: creation_time : 2019-09-18T09:27:36.000000Z handler_name : Time Code Media Handler reel_name : Untitled timecode : 00:58:04:15 Stream #0:2(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32 (24 bit), 1152 kb/s (default) Metadata: creation_time : 2019-09-18T09:27:36.000000Z handler_name : Apple Sound Media Handler Stream #0:3(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32 (24 bit), 1152 kb/s (default) Metadata: creation_time : 2019-09-18T09:27:36.000000Z handler_name : Apple Sound Media Handler File 'output.mov' already exists. Overwrite ? [y/N] y Stream mapping: Stream #0:2 (pcm_s24le) -> join:input0 Stream #0:3 (pcm_s24le) -> join:input1 join -> Stream #0:0 (pcm_s24le) Press [q] to stop, [?] for help Output #0, mov, to 'output.mov': Metadata: encoder : Lavf58.23.102 Stream #0:0: Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, stereo, s32, 23 04 kb/s (default) Metadata: encoder : Lavc58.41.101 pcm_s24le size= 282kB time=00:00:01.00 bitrate=2309.9kbits/s speed=41.1x video:0kB audio:281kB subtitle:0kB other streams:0kB global headers:0kB muxing o verhead: 0.256944% What is the best way to verify that the process was lossless? I tried the following which seems very clumsy: 1. Export the two original audio tracks as seperate wav files with (i know i could have done it in one command but I just knocked this together) ffmpeg -i input.mov -c:a copy -t 1 -map 0:2 left.wav ffmpeg -i input.mov -c:a copy -t 1 -map 0:3 right.wav 2. Export the new output.mov with the single stereo track as a WAV, then used the following to make seperate tracks out of the channels: with ffmpeg -i output.mov -c:a pcm_s24le -map_channel 0.0.0 left_merge.wav -c:a pcm_s24le -map_channel 0.0.1 right_merge.wav 3. Use framemd5s to compare the various wavs to make sure that the same samples are produced in the source and output. The framemd5s were indeed identical aside from the last sample, which may have had something to do with trimming at 1 second. is there an easier way to verify that the same audio is produced in the source audio files as with the merged stereo track? Best, Kieran. ------ This email has been scanned for spam and malware by The Email Laundry. _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".