Format of BBC Radio 4 .m4a files

michael norman michaeltnorman at
Sat Sep 12 04:00:34 PDT 2015

On 11/09/15 18:37, Jim web wrote:
> In article
> <CAJEH5C3hnMfJsWYci2EYrz1Wi-2uh823aqHaaMjLP6Weu07f3A at>, Jon
> Davies <jon at> wrote:
>> On 9 September 2015 at 12:28, Jim web <web at> wrote:
>>> Why not flac?
>> because as others have pointed out, the raw data downloaded from the bbc
>> is aac.  you can't improve the quality by removing compression,
> I can't recall saying otherwise.
>> all this will do is occupy more space on your disk.  All get_iplayer
>> does by default is re-package the (unchanged) aac data in an mp4 file.
> Yes. For the avoidance of doubt I should add that I did know that. :-)
>> If you ask get_iplayer for mp3 then whether it was built to transcode
>> directly from the original aac or via flac would make no difference
>> whatsoever.
> I think you've misunderstood the point of my question. Alas you've
> also now removed the context so I have to add it back in the following..
> If your player can't play the mp4a and you *need* to transcode the basic
> choice is simple. You either:
> A) transcode to some other 'lossy' format like mp3. This will be almost
> certain to lose details.
> or
> B) transcoder to a loss-free format like flac (or lpcm wave). This can be
> done with *no* loss of details.
> You've now snipped the context which was that mp4a wasn't playable on the
> player. That's the basis of the discussion.
> So, because "leave it as mp4a" is taken not to be a useful option by the
> conditions of the situation, the above choice may be unavoidable in the
> circumstances. OTOH if you *can* play mp4a then obviously no transcoding is
> necessary (except during replay).
> So the point of my question was to find out if there was a reason why, *in
> this situation where mp4a won't play*, you can't (or don't wish to) choose
> flac. (B) allows the user to avoid more loss, not wave a wand to recover
> what wasn't present in the mp4a.
> Jim
If you have mp4a files which will not play on a chosen device then you 
need to either find a device that will play them or save them and 
transcode them into a format your existing device will play them. 
Obviously if you transcode from one lossy format to another you will 
alter the original to its detriment.  As Jim says transcoding to flac 
will result in a bigger file, but will not throw anything away. 
Personal music players that will play anything are not hard to find.

My favorite is this

Expensive ? perhaps, depends what you want. One thing it does do is play 
mp4a radio progs, I know I just tried it.


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