Usually, they use decoder chips which are basically mass produced SOCs. You can find those chips on stand-alone media players as well, those little boxes that have a few USB ports, probably eSATA, and one or more HDMI outputs. Sometimes, the same chips are also in modern TV sets, and those are usually build into DVD players as well. There, the DVD is accessed like a mass-storage device, but the decoding part is one of those SOCs.Now, the cheapest SOCs are those that are also used in mobile media players (we used to call them "MP3 players"). Those media players can decode only a couple of files and codecs, and that's because of cheap decoder chips. Since one of those cheapie decoders are used in most DVD/BR players, they also can decode only just a few file formats and codecs.
The SOCs used in these devices contain ordinary CPUs running software decoders. If they don't support a given audio format, its because no decoder software for it was provided by the vendor.
I'd say the most likely explanation is that they simply don't think there's enough demand for it.
Quote from: saratoga on 13 January, 2012, 11:34:58 AMThe SOCs used in these devices contain ordinary CPUs running software decoders. If they don't support a given audio format, its because no decoder software for it was provided by the vendor.Erm, I can assure you, that my i.Beat Organix from TrekStor uses a SOC, with integrated DSP that directly interfaces with the headphone amp. So there's not much software decoding going on.
I believe, to cut cost, they use cheap stuff with hardly any decoding capabilities other than VOB and the contained codecs. I know for a fact, that there are BluRay SOCs. that do basically only decode BluRay and DVD decoding work, with nothing else. It's a very cost effective solution for very cheap china DVD/BD players.
krafty, in case you're looking for a good media player, don't buy a BD player, just get yourself a media box, like the one from WD, or Popcorn Hour.
I remember back in the day the company that made the chips inside of the 3G (or 4G) iPod worked with WMA but Apple locked that out through the iPod's firmware.
Incidentally, the reason so many of these devices won't support gapless decoding is that the company in question would have to actually license the source code to add the feature
Quote from: saratoga on 16 January, 2012, 09:41:04 PMIncidentally, the reason so many of these devices won't support gapless decoding is that the company in question would have to actually license the source code to add the featureCould you explain that in more detail?I thought gapless playback was simply a matter of programming (perhaps adding a bit of buffering or whatever..). How does licensing come into play?
Not sure if you realize this, but a SOC is a device with a CPU, memory, and software. Basically SOC == computer on a chip. By definition, SOCs are re-programmable.
The line between "programmable" and "fixed function" can be blurry. A dsp is perhaps more specialized than an Intel chip - depending on your definition of generality.
If a chip contains a low-power general-purpose cpu + fixed-function fft/transforms, it still may not be flexible enough to be software reconfigured to do flac, even though it may be able to decode a given (complex) lossy format.
Not really. A DSP is still generally going to be Turing complete, a fixed function device is not. Thats a pretty well defined line. You will of course have fixed function devices too; at very least any audio device must have a DAC, but that doesn't somehow make the CPU less flexible.
Quote from: knutinh on 18 January, 2012, 11:24:30 AMIf a chip contains a low-power general-purpose cpu + fixed-function fft/transforms, it still may not be flexible enough to be software reconfigured to do flac, even though it may be able to decode a given (complex) lossy format.No, such a device would still be able to decode FLAC quite easily. FLAC is extremely fast, and FFTs occupy only a small portion of decode time for MP3, so the main CPU would have to be plenty fast.Never mind that no actual SOC works like that
>> How difficult do you guys think it would be to recode FLAC to run on a>> microcontroller like an AVR?> > Completely unrealistic. May be, the mono @ 8kHz decoder will fit> although I doubt about it.
"There is an ever demanding need to develop low power audio devices using MP3 technology. From the profiled results of MP3 algorithm on ARM processors, it has been observed that the synthesis filter bank in the audio decoder consumes maximum power. "
Having a pentium4 system with the latest Nvidia Cuda-capable GPU might serve as an example. The complete system can run any application, and will have a massive theoretical flop performance. It may still be sluggish running Photoshop or anything else that is not able to take full advantage of that GPU (either due to lack of programmer resources, or because the task maps poorly to the specialized design of GPUs).
Google returned this:
I've been watching recent releases of Blu-Ray players and most of them just ignore lossless formats like FLAC
Quote from: Brand on 13 January, 2012, 11:07:33 AMI'd say the most likely explanation is that they simply don't think there's enough demand for it.It will remain a niche codec until someone like Microsoft or Apple embraces it, which isn't likely to happen.