Today I had to convert audio messages from a NEC pbx to the format a 3cx pbx uses.
These are the digital audio intro messages etc. that you get when you call e.g. the main telephone number of a company.
They were in the wrong format, and in such state, 3cx does not eat it.
From the NEC we got 8 bit 1 channel (mono) PCM files.
3CX accepts only 16 bit one channel (mono) PCM. Sample rate on both is 8k.
Don’t we love ffmpeg. Fixed!
I have an virus-unchecked exe for windows here if you like, just remove extension .file after download 🙂
Next cmd will fix this: welkcome123.wav was the audio file retrieved from the NEC SV8100.
ffmpeg -i welcome123.wav -acodec pcm_s16le -ac 1 -ar 8000 welcome123-16b.wav
See, it made the file approx twice the size 🙂
Not strange when you make 8 bits into 16 bits….
Input #0, wav, from 'welcome123.wav': Duration: 00:00:12.29, bitrate: 64 kb/s Stream #0:0: Audio: pcm_alaw ( / 0x0006), 8000 Hz, mono, s16, 64 kb/s Output #0, wav, to 'welcome123-16b.wav': Metadata: ISFT : Lavf57.51.100 Stream #0:0: Audio: pcm_s16le ( / 0x0001), 8000 Hz, mono, s16, 128 kb/s Metadata: encoder : Lavc57.58.100 pcm_s16le Stream mapping: Stream #0:0 -> #0:0 (pcm_alaw (native) -> pcm_s16le (native)) Press [q] to stop, [?] for help size= 192kB time=00:00:12.28 bitrate= 128.1kbits/s speed=7.52e+003x video:0kB audio:192kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.039681%
NEC manual here if you like to see how that works.
I hope it may help you as well. Maybe not. who knows.