[FFmpeg-devel] [PATCH] AAC: type puns for 16 bit floating point rounding
Sat Dec 13 14:10:33 CET 2008
On Wed, Dec 10, 2008 at 12:04 AM, Alex Converse <alex.converse at gmail.com> wrote:
> On Tue, Dec 9, 2008 at 5:58 PM, Robert Swain <robert.swain at gmail.com> wrote:
>> 2008/12/9 Guillaume POIRIER <poirierg at gmail.com>:
>> > Hello,
>> > On Tue, Dec 9, 2008 at 7:27 PM, Robert Swain <robert.swain at gmail.com>
>> >> 2008/12/9 Guillaume POIRIER <poirierg at gmail.com>:
>> >> Grab:
>> >> or some other am* file from there, though not am02* as there's a known
>> >> bug with those at the moment.
>> > These samples are too short, so I'm afraid that I'm measuring ffmpeg's
>> > startup time rather than AAC decoding (it takes about .2 seconds to
>> > decode the file, from launch of FFmpeg to exit).
>> > Would it work with any iTunes-encoded AAC file? If not, maybe you
>> > should direct me to a bigger sample from Mplayer's samples
>> > collections...
>> It needs to be an AAC Main profile file. iTunes files are LC AAC as
>> are most other AAC streams in the wild. If I find a longer sample,
>> I'll let you know. In the mean time, thanks for trying. :)
> A longer sample can be made with mp4box as follows.
> mp4box -raw 1 am00_48.mp4
> cat am00_48_track1.aac am00_48_track1.aac (...) > out.aac
> mp4box -add out.aac out.mp4
Thanks for the tip; On my PPC970, decoding is a bit faster (around 1%).
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