[InternetSandman]

I recently got an HDP-R10 and just stuffed it (and a 64gb memory card) with the majority of my lossless library and a couple MP3 CD's. the battery life monitor has been sketchy at best (turn it off at 50%, turn it back on and see 30%) but I've noticed on occasion when listening to some of the higher resolution jazz and classical albums (mostly 24/96, a couple 24/192)that the battery life seems to drop faster. Is this true or just a trick of the mind? I like making it last for my whole workday so that's why I ask, and if it does play a factor, is there a way to down sample my higher res files to something around 24/44.1 or even 16/44 if bit depth matters a lot? I'm not listening in a particularly quiet environment (using my earphones as earplugs along with earmuffs) so sound quality suffers either way

 

[mvrk10256]

It stands to reason that different file formats require different codecs - and depending on the algorithm the efficiency of transcription can change. I have not noticed a serious difference on my Sansa though. 

 

[Sefelt103]

I've always found it slightly odd that file size affects battery life but it does. My T51/SFlo2 gives 9hrs playing mp3s and 6hrs playing flac. The greater processing required to handle more data in real time drains the battery faster. It generates more heat as well. I read a review about iRiver's AK100 which suggested there was only miniscule improvements in sound quality going from 16/44 to 24/96 or 24/192. If you are listening in a noisy environment then you may as well have the extra space and battery duration that mp3 offers.

 

[brhfl]

Quote:

I've always found it slightly odd that file size affects battery life but it does. 

 
Well, no. As you, the OP, and the poster above you mention, you're not comparing file size... You're talking about completely different codecs, completely different algorithms. FLAC and ALAC are pretty impressive to get the file size down to what they do while remaining lossless - it's bound to be a more difficult task to unpack that vs. a format which gets its efficiency by getting rid of information (anything lossy)... 

 

[DMinor]

One of my ipod videos' has set the record at almost 32 hrs of running time before charge (see the pic below). I swapped the stock hdd with a 128GB CF card (with the Tarkan adapter) and the battery wasn't even new. All playing 16bit flac's.
 
 

 

[Sefelt103]

So it's not the file size but rather the extra processing required to extract a lossless file as opposed to a lossy one.Thats interesting, thanks brhfl.

 

[InternetSandman]

Well, no. As you, the OP, and the poster above you mention, you're not comparing file size... You're talking about completely different codecs, completely different algorithms. FLAC and ALAC are pretty impressive to get the file size down to what they do while remaining lossless - it's bound to be a more difficult task to unpack that vs. a format which gets its efficiency by getting rid of information (anything lossy)... 

Are you suggesting that a WAV file at 24/192 would be easier on the battery than FLAC or ALAC at the same resolution, as there's no decompression involved?

 

[Achmedisdead]

Quote:

Are you suggesting that a WAV file at 24/192 would be easier on the battery than FLAC or ALAC at the same resolution, as there's no decompression involved?

Surely that would be offset somewhat by increased seeking to keep the buffer filled.....especially on a hard drive player.

 

[InternetSandman]

Quote:

Surely that would be offset somewhat by increased seeking to keep the buffer filled.....especially on a hard drive player.

But what about flash memory? My current DAP has a total of 128GB of flash, I'd assume seeking would have much less of an impact on solid state storage than on mechanical storage. Really the only concern would be less space for each album

 

[JK1]

File size does also make a difference though. I listened to podcasts on my Clip+ at 32kbps mono and got around 17 hour battery life using the original firmware. Playing 256kbps mp3 music files got me only around 12 to 13 hours.

 

[InternetSandman]

Quote:

File size does also make a difference though. I listened to podcasts on my Clip+ at 32kbps mono and got around 17 hour battery life using the original firmware. Playing 256kbps mp3 music files got me only around 12 to 13 hours.

You misunderstand. That's not file size, that's bit rate, but essentially yes that's a good example, the higher quality music being a bigger drain on the battery 

 

[JK1]

Quote:

You misunderstand. That's not file size, that's bit rate, but essentially yes that's a good example, the higher quality music being a bigger drain on the battery 

A smaller file size is the same thing as saying a smaller bit rate for constant bitrate mp3 files of the same play time.

 

[brhfl]

Quote:

A smaller file size is the same thing as saying a smaller bit rate for constant bitrate mp3 files of the same play time.

It's the same only under those specific circumstances, which is why making the broader statement, 'File size does also make a difference though' is misleading. 
 
To the earlier question of WAV vs. FLAC (and that itself vs. FLAC and MP3), it's complicated. Access may very well make a difference, but how much compared to processor overhead? Drive access will depend on tech involved (that is, HDD or SSD), vs the question of the efficiency of the processor, efficiency of the decompressor, etc. Playing back an uncompressed WAV should be a far simpler task, and processor overhead should reflect that, whether it outweighs the cost of drive access is another question. But it is certainly different.
 
Consider, as a thought exercise in a rather unrelated example, filesystem-level compression designed to be transparent to the user. Not for the sake of saving space, per se, but for the sake of wasting less time on the bottleneck that was HDD & bus speeds. When processors were at the point that they could decompress more quickly than HDDs could offer the uncompressed data... There are always a few pieces of the puzzle to fit together.

 

[Stevemitchell]

From the developer of PowerAmp regarding high-bit-rate-depth FLACs.  I seem to remember him also saying that Android kernel code only allowed for 44/48KHz/16bit resolution.  Maybe that's changed.
 
Current Poweramp has 144khz limit for flacs. Such flacs generally resampled by Poweramp to device output sampling rate (44.1 / 48 khz). Also, such high rate files are not generally recommended for portable devices (due to x4-x5 cpu/battery consumption), still, we already changed that sample frequency limit to 256khz in current Poweramp dev. builds.
 
Steve