Power consumption when playing differents music formats

[ursamajor]

Hi everybody!
Firstly, I would like to congratulate and thank all the creators and contributors of this exceptional alternative to the original firmware. Yesterday I installed it on my brand new Sansa Clip Zip and I'm completely satisfied of it.
Is there somewhere a comparison between the power consumption when using different formats? I just saw on Sandisk forum a comparison between ogg vorbis and mp3 lame, but using original firmware. mp3 seemed to win by ~33% (12h vs. 8h).

Thanks in advance!


PS: excuse, please, my poor english, I'm not a native english speaker.

[saratoga]

Every format will get much better battery life than the Sandisk firmware. There may be some minor difference between mp3 and vorbis but probably not much. They are about the same time to decode.

[ursamajor]

Thank you for the prompt answer. Is there something else to set for better battery life? I ask this because I didn't get good performance on my Clip Zip battery. Only 7-9 hours of continuous music playing, considering that at a moderate music volume (-38dB), using brightness at 1 and a theme whose dominant color is black (Cleanzip).

[saratoga]

We will be improving power management soonish which should give you a large increase.  But if you're only getting 7 hours in rockbox, you're probably getting only 5 or less in the Sandisk firmware which would be a nearly dead battery. 

[ursamajor]

But the player is brand new. Maybe (I  suppose) the battery it's in its first cycles of recharging, when it's achieve the full performance? Just performed 3 cycles of recharge. Now I can see on Rockbox that the playback time is 5h49min and battery is 52% and 8h12min (I believe) estimated time of discharging. It'll be a good improve, from 9 to 14-15h. 

[saratoga]

If the numbers you posted above are just estimates then they don't really mean anything. You need to completely discharge the battery to know how long it will last.

[ursamajor]

I understand. So, the Rockbox cannot estimate more or less the remaining time of the battery?
I'll post here the running time. I hope my assumption is correct and the battery life will improve after some cycles of recharge.

[404_user_not_found]

Is there somewhere a comparison between the power consumption when using different formats?

1)
If you search low demand lossy codec with best quality - MusePack. Not usable without doing a transcode.
The best lossless codec with low demand - FLAC. Avoid using hi-rez formats because they make no sense for increasing a quality of music and not supported by hardware of player. They can be played, but they will be converted on the fly to supported format with worst method resulting a poor audio quality and more power consumption.

2)
Decode Test
The rule is simple. Less MHz needed to decode the file at 1.0x real time, less power consumption.

[ursamajor]

Indeed, I know about musepack. It's my favourite format. Still I have musepack music from years ago. For me it sounds better. On the other hand, I didn't know that it's so low power consumption. Thank you. For portable use probably I'll reencode my flac's in musepack.