[Libav-user] QTKit -> Libav: has it ever been done?

[Paul B Mahol]

On 3/27/13, Brad O'Hearne <brado at bighillsoftware.com> wrote:
> On Mar 27, 2013, at 1:08 PM, Paul B Mahol <onemda at gmail.com> wrote:
>> Than use AV_SAMPLE_FMT_FLTP, you do not need to manually interleave
>> samples.
>> Each channel samples are put into separate frame->data[X] where X is
>> channel
>> number starting from 0.
>
> Hey thanks for the idea, Paul, I'll give it a shot! The resampling will
> still be converting floats to signed 16-bits, so I am very interested in
> exactly the conversion that is taking place here. I would think it shouldn't
> be just casting or truncating, it should be scaling the sample value based
> on the available storage space. Given 32-bit to 16-bit conversion, and that:
>
> Signed 16-bit (I'm assuming integral) = From  -32,768 to 32,767, or from
>  -(2^15) to 2^15  - 1
>
> and
>
> 32-bit float = (I'm just going to post a Wikipedia link here for brevity,
> but a float has one bit for sign, 8 bits for exponent, and 23 bits for float
> data): http://en.wikipedia.org/wiki/Single-precision_floating-point_format
>
> So I'm curious -- how is libswresample converting from float to signed
> 16-bit?

There is source, why dont you take look yourself.

>
> Thx,
>
> Brad
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