Hi Jeremy and thanks for the quick answer (and sorry for the not very precise report) - I'm on OSX Mojave 10.14.6 - sox has been installed through brew `brew install sox` - `sox --version` gives `sox: SoX v` - `brew info sox`gives ``` sox: stable 14.4.2 (bottled) SOund eXchange: universal sound sample translator https://sox.sourceforge.io/ /usr/local/Cellar/sox/14.4.2_3 (23 files, 1.8MB) * Poured from bottle on 2019-05-17 at 16:19:01 From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/sox.rb ==> Dependencies Build: pkg-config ✔ Required: flac ✘, lame ✔, libpng ✔, libsndfile ✔, libvorbis ✔, mad ✔, opusfile ✘ ==> Analytics install: 2,592 (30 days), 7,521 (90 days), 36,263 (365 days) install-on-request: 2,436 (30 days), 7,051 (90 days), 32,403 (365 days) build-error: 0 (30 days) ``` - SOX_OPTS is empty when I `echo $SOX_OPTS` If I launch ``` sox -V3 vocals.wav vocals-V3.mp3 ``` I get ``` sox: SoX v sox INFO formats: detected file format type `wav' Input File : 'vocals.wav' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors File Size : 31.8M Bit Rate : 1.41M Sample Encoding: 16-bit Signed Integer PCM Endian Type : little Reverse Nibbles: no Reverse Bits : no sox INFO sox: Overwriting `vocals-V3.mp3' sox INFO mp3: using MP3 encoding defaults Output File : 'vocals-V3.mp3' Channels : 2 Sample Rate : 44100 Precision : 24-bit Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors Sample Encoding: MPEG audio (layer I, II or III) Comment : 'Processed by SoX' sox INFO sox: effects chain: input 44100Hz 2 channels sox INFO sox: effects chain: output 44100Hz 2 channels ``` Which seems good but when I do ``` soxi vocals-V3.mp3 ``` I still get a different number of samples and duration ``` Input File : 'vocals-V3.mp3' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.04 = 7939544 samples = 13502.6 CDDA sectors File Size : 2.88M Bit Rate : 128k Sample Encoding: MPEG audio (layer I, II or III) ``` I notice that the precision is different and if I launch ``` sox -V3 vocals.wav -b 24 vocals-V3.mp3 ``` It ends up with the same result ``` sox: SoX v sox INFO formats: detected file format type `wav' Input File : 'vocals.wav' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors File Size : 31.8M Bit Rate : 1.41M Sample Encoding: 16-bit Signed Integer PCM Endian Type : little Reverse Nibbles: no Reverse Bits : no sox WARN formats: mp3 can't encode to 24-bit sox INFO mp3: using MP3 encoding defaults Output File : 'vocals-V3.mp3' Channels : 2 Sample Rate : 44100 Precision : 24-bit Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors Sample Encoding: MPEG audio (layer I, II or III) Comment : 'Processed by SoX' sox INFO sox: effects chain: input 44100Hz 2 channels sox INFO sox: effects chain: output 44100Hz 2 channels ``` but ``` soxi vocals-V3.mp3 ``` still gives ``` Input File : 'vocals-V3.mp3' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.04 = 7939544 samples = 13502.6 CDDA sectors File Size : 2.88M Bit Rate : 128k Sample Encoding: MPEG audio (layer I, II or III) ``` Here a try with V4 ```sox -V4 vocals.wav vocals-V4.mp3 && soxi vocals-V4.mp3``` ``` sox: SoX v time: Jan 9 2019 13:31:37 uname: Darwin MBP-de-Martin 18.7.0 Darwin Kernel Version 18.7.0: Tue Aug 20 16:57:14 PDT 2019; root:xnu-4903.271.2~2/RELEASE_X86_64 x86_64 compiler: gcc 4.2.1 Compatible Apple LLVM 10.0.0 (clang-1000.11.45.5) arch: 1288 48 88 L sox INFO formats: detected file format type `wav' sox DBUG wav: Searching for 66 6d 74 20 sox DBUG wav: WAV Chunk fmt sox DBUG wav: Searching for 64 61 74 61 sox DBUG wav: WAV Chunk data sox DBUG wav: Reading Wave file: Microsoft PCM format, 2 channels, 44100 samp/sec sox DBUG wav: 176400 byte/sec, 4 block align, 16 bits/samp, 31752000 data bytes sox DBUG wav: 7938000 Samps/chans sox DBUG wav: Searching for 4c 49 53 54 Input File : 'vocals.wav' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors File Size : 31.8M Bit Rate : 1.41M Sample Encoding: 16-bit Signed Integer PCM Endian Type : little Reverse Nibbles: no Reverse Bits : no sox DBUG mp3: -C option is inf sox INFO mp3: using MP3 encoding defaults Output File : 'vocals-V4.mp3' Channels : 2 Sample Rate : 44100 Precision : 24-bit Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors Sample Encoding: MPEG audio (layer I, II or III) Comment : 'Processed by SoX' sox INFO sox: effects chain: input 44100Hz 2 channels (multi) 16 bits 00:03:00.00 sox INFO sox: effects chain: output 44100Hz 2 channels (multi) 24 bits 00:03:00.00 sox DBUG sox: start-up time = 0.001929 Input File : 'vocals-V4.mp3' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.04 = 7939544 samples = 13502.6 CDDA sectors File Size : 2.88M Bit Rate : 128k Sample Encoding: MPEG audio (layer I, II or III) ``` And same with V5, V6 etc.. For the trimming I noticed there are 1544 more samples in the resulting mp3 file, so I tried to trim them using this command ``` sox -V3 vocals.mp3 vocals-trimmed.mp3 trim 1544s && soxi vocals-trimmed.mp3 ``` which gives ``` sox: SoX v Input File : 'vocals.mp3' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.04 = 7939544 samples = 13502.6 CDDA sectors File Size : 2.88M Bit Rate : 128k Sample Encoding: MPEG audio (layer I, II or III) sox INFO sox: Overwriting `vocals-trimmed.mp3' sox INFO mp3: using MP3 encoding defaults Output File : 'vocals-trimmed.mp3' Channels : 2 Sample Rate : 44100 Precision : 24-bit Sample Encoding: MPEG audio (layer I, II or III) Comment : 'Processed by SoX' sox INFO sox: effects chain: input 44100Hz 2 channels sox INFO sox: effects chain: trim 44100Hz 2 channels sox INFO sox: effects chain: output 44100Hz 2 channels Input File : 'vocals-trimmed.mp3' Channels : 2 Sample Rate : 44100 Precision : 16-bit Duration : 00:03:00.01 = 7938397 samples = 13500.7 CDDA sectors File Size : 2.88M Bit Rate : 128k Sample Encoding: MPEG audio (layer I, II or III) ``` So "it does not work" means, the resulting file is not exactly trimmed of 1544s as expected because there are 1147 left It takes approximately 3s I hope the description is clearer Let me know if I can give you more information Thanks ----------------------------------------------------------------------- *Martin RATINAUD* ----------------------------------------------------------------------- On Wed, Dec 11, 2019 at 9:39 PM Jeremy Nicoll - ml sox users < jn.ml.sxu.88@wingsandbeaks.org.uk> wrote: > On 2019-12-11 14:26, Martin Ratinaud wrote: > > Hi all, > > > > I'm converting a file called vocals.wav to vocals.mp3 > > vocals.wav > > < > https://drive.google.com/file/d/1he1eCJag1G8iGkgL932jy_mXuLT_khGM/view?usp=drive_web > > > > For this I'm using this command > > > > ``` > > sox vocals.wav vocals.mp3 > > ``` > > and here is the result of the corresponding files > > > > - original file > > ``` > > soxi /Users/martin/Downloads/split-test/vocals.wav > > > > Input File : '/Users/martin/Downloads/split-test/vocals.wav' > > Channels : 2 > > Sample Rate : 44100 > > Precision : 16-bit > > Duration : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors > > File Size : 31.8M > > Bit Rate : 1.41M > > Sample Encoding: 16-bit Signed Integer PCM > > ``` > > > > - converted file > > ``` > > soxi /Users/martin/Downloads/split-test/vocals.mp3 > > > > Input File : '/Users/martin/Downloads/split-test/vocals.mp3' > > Channels : 2 > > Sample Rate : 44100 > > Precision : 16-bit > > Duration : 00:03:00.04 = 7939544 samples = 13502.6 CDDA sectors > > File Size : 2.88M > > Bit Rate : 128k > > Sample Encoding: MPEG audio (layer I, II or III) > > ``` > > > > You can see that the duration is not the same which is weird and the > > number > > of samples also changed. > > In fact, 1544 samples have been added to the beginning of the file > > > Which version of sox, on what OS? > Did you build the sox binary yourself or download it from somewhere? > > Although you say the command was just > > sox vocals.wav vocals.mp3 > > sox can also incorporate values of environment variables. Is there any > chance that on your OS the command has included any other parameters? > See the 'SOX_OPTS' section of the manual. > > > If you reissue the command, as eg > > sox -V3 vocals.wav vocals002.mp3 > > (or even -V4 or more) do any of the info messsages give any clues? Is > the > result file the same size as your one? > > > > > > If I try to launch `sox -V vocals.mp3 vocals-trimmed.mp3 trim 1544s` it > > does not work > > You'll need to be more precise. What sort of "not work"? Does sox > run? > Does it produce any messages? Is there a result file? How long was it? > > > -- > Jeremy Nicoll - my opinions are my own > > > _______________________________________________ > Sox-users mailing list > Sox-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/sox-users >