[FFmpeg-user] G.726 codeword packing

[Paul B Mahol]

On 9/2/13, Arthur Grant <arthur.grant1969 at gmail.com> wrote:
> I have a question about G.726 codeword packing.
> I'm using the following command to convert 16bit, 8kHz, 1channel LPCM into
> a G.726
>
> ffmpeg -i 8k16bitpcm.wav -codec g726  out_g726.wav
>
> The output file is with wFormatTag = 0x0045 (AV_CODEC_ID_ADPCM_G726)
> The output G.726 is using AAL2 type codeword packing.
> My question is why the output is using AAL2 type codeword packing?
> The other type of codeword packing is as in RFC355. I checked the source
> code libavcodec\g726.c and it looks like that the implementation always
> uses the AAL2 type codeword packing.
>
> Which standard or specification states that G.726 in WAVE should use AAL2
> type codeword packing?

Which standard or specification states it should use something else?