Rockbox General > Rockbox General Discussion

Which sound format uses CPU the least?

<< < (2/4) > >>

r00tb33r:

--- Quote from: dreamlayers on April 12, 2009, 01:32:54 AM ---
--- Quote from: r00tb33r on April 12, 2009, 01:00:54 AM ---How do I know which sampling rate say Gigabeat rockdoom uses?

--- End quote ---

You can look at the configuration header file for your player.  For example, if you mean Gigabeat F, that would be firmware/export/config-gigabeat.h.  There, search for HW_SAMPR_CAPS.  For the Gigabeat F, that is:

--- Code: ---#define HW_SAMPR_CAPS (SAMPR_CAP_88 | SAMPR_CAP_44 | SAMPR_CAP_22 | \
                       SAMPR_CAP_11)

--- End code ---
SAMPR_CAP_11 means 11 KHz, or more accurately 11025 Hz.  Since that is present, Rockdoom will use it.  If it wasn't there, Rockdoom would use 44100 Hz.

--- End quote ---
What's the advantage of 11KHz on a target as fast as Gigabeat?  It doesn't actually sound too good at all.  Anything less than 22KHz causes a very noticeable degradation in sound quality.  Why not use the sampling rate of the original sounds?
According to http://doom.wikia.com/wiki/Sound some Doom sounds have a sampling rate of 22KHz, which explains the degradation I noticed.
It shouldn't be too hard to force a higher sampling rate right?

dreamlayers:

--- Quote from: r00tb33r on April 12, 2009, 05:02:56 AM ---What's the advantage of 11KHz on a target as fast as Gigabeat?  It doesn't actually sound too good at all.  Anything less than 22KHz causes a very noticeable degradation in sound quality.  Why not use the sampling rate of the original sounds?
According to http://doom.wikia.com/wiki/Sound some Doom sounds have a sampling rate of 22KHz, which explains the degradation I noticed.
It shouldn't be too hard to force a higher sampling rate right?

--- End quote ---

It's very easy to force a higher sampling rate.  Look near the start of apps/plugins/doom/i_sound.c.  In particular, this decides the sampling rate at compile time:

--- Code: ---#ifdef HW_HAVE_11
#define SAMPLERATE  SAMPR_11 // 44100 22050 11025
#else
#define SAMPLERATE  SAMPR_44 // 44100 22050 11025
#endif

--- End code ---

I feel that sound in plugins skips too easily, even when the CPU is fast enough.  Regardless, you ought to be able to do 22 KHz on a Gigabeat F.

r00tb33r:

--- Quote from: dreamlayers on April 12, 2009, 10:16:54 AM ---
--- Quote from: r00tb33r on April 12, 2009, 05:02:56 AM ---What's the advantage of 11KHz on a target as fast as Gigabeat?  It doesn't actually sound too good at all.  Anything less than 22KHz causes a very noticeable degradation in sound quality.  Why not use the sampling rate of the original sounds?
According to http://doom.wikia.com/wiki/Sound some Doom sounds have a sampling rate of 22KHz, which explains the degradation I noticed.
It shouldn't be too hard to force a higher sampling rate right?

--- End quote ---

It's very easy to force a higher sampling rate.  Look near the start of apps/plugins/doom/i_sound.c.  In particular, this decides the sampling rate at compile time:

--- Code: ---#ifdef HW_HAVE_11
#define SAMPLERATE  SAMPR_11 // 44100 22050 11025
#else
#define SAMPLERATE  SAMPR_44 // 44100 22050 11025
#endif

--- End code ---

I feel that sound in plugins skips too easily, even when the CPU is fast enough.  Regardless, you ought to be able to do 22 KHz on a Gigabeat F.

--- End quote ---
Perfect!  SAMPR_22 sounds much better.  No reason for higher sampling rate since the WAD does not contain sounds of higher sampling rate than 22KHz.

Do you know how/why/where RockDoom stops music playback?  I have low bitrate mp3s that I would like to hear playing to see if Gigabeat F can handle both.
Thanks so far!

Llorean:
It stops playback because there's not a system for sharing the playback buffer. Doom needs more of the RAM than the normal amount plugins are allocated and it's an all or nothing deal.

nls:

--- Quote from: r00tb33r on April 12, 2009, 01:00:54 AM ---How CPU intensive is MidiPlay?

--- End quote ---

I'd guess only the gigabeat f and s would be fast enough to play midi with midiplay while running doom. (it's rather cpu intensive and only barely realtime on some targets)

Navigation

[0] Message Index

[#] Next page

[*] Previous page

Go to full version