I just got MPlayer working on my Fedora Core 1 box. The video is very nice, but the sound is choppy, with a lot of poppiness in the background. I am using ALSA v1.0.4, and don't have this problem with other apps like Rhythmbox. Anyone else ever have a similar problem? What can I do about it? Thanks for any insight.

How are you running mplayer? What settings/command are you using? What is the textual output of mplayer when you try to play something?

I'm just using the following command:

mplayer file.whatever

I do this from a terminal window, and the video plays just fine. When I start it, it prints this out:

MPlayer 1.0pre4-3.3.2 (C) 2000-2004 MPlayer Team

CPU: Advanced Micro Devices Athlon MP/XP/XP-M Barton 2787 MHz (Family: 6, Stepping: 0)
Detected cache-line size is 64 bytes
CPUflags: MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE

Reading config file /usr/local/etc/mplayer/mplayer.conf: No such file or directory
Reading config file /home/ben/.mplayer/config
Reading /home/ben/.mplayer/codecs.conf: Can't open '/home/ben/.mplayer/codecs.conf': No such file or directory
Reading /usr/local/etc/mplayer/codecs.conf: Can't open '/usr/local/etc/mplayer/codecs.conf': No such file or directory
Using built-in default codecs.conf.
font: can't open file: /home/ben/.mplayer/font/font.desc
font: can't open file: /usr/local/share/mplayer/font/font.desc
Linux RTC init error in ioctl (rtc_irqp_set 1024): Permission denied
Try adding "echo 1024 > /proc/sys/dev/rtc/max-user-freq" to your system startup scripts.
Using usleep() timing
Can't open input config file /home/ben/.mplayer/input.conf: No such file or directory
Can't open input config file /usr/local/etc/mplayer/input.conf: No such file or directory
Falling back on default (hardcoded) input config

Playing file.whatever
QuickTime/MOV file format detected.
--------------
MOV track #0: 31020 chunks, 185914 samples
MOV: Found MPEG4 movie Elementary Stream Descriptor atom (86)!
Image size: 720 x 360 (32 bpp)
Display size: 874 x 360
Fourcc: mp4v Codec: '3ivx D4 4.5'
--------------
MOV track #1: 37186 chunks, 333948 samples
Audio bits: 16 chans: 2 rate: 44100
Audio extra header: len=111 fcc=0x77617665
MOV: Found MPEG4 audio Elementary Stream Descriptor atom (51)!
Fourcc: mp4a
--------------
MOV track #2: 33 chunks, 33 samples
Generic track - not completly understood! (id: 2)
--------------
MOV: longest streams: A: #1 (333948 samples) V: #0 (185914 samples)
Clip info:
copyright: 2003
comments: Encoded by xen0bear
name: file.whatever
==========================================================================
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
FAAD: compressed input bitrate missing, assuming 128kbit/s!
AUDIO: 44100 Hz, 2 ch, 16 bit (0x10), ratio: 16000->176400 (128.0 kbit)
Selected audio codec: [faad] afm:faad (FAAD AAC (MPEG2/MPEG4 Audio) decoder)
==========================================================================
vo: X11 running at 1024x768 with depth 24 and 32 bpp (":0.0" => local display)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffodivx] vfm:ffmpeg (FFmpeg MPEG-4)
==========================================================================
Checking audio filter chain for 44100Hz/2ch/16bit -> 44100Hz/2ch/16bit...
AF_pre: af format: 2 bps, 2 ch, 44100 hz, little endian signed int
AF_pre: 44100Hz 2ch Signed 16-bit (Little-Endian)
AO: [oss] 44100Hz 2ch Signed 16-bit (Little-Endian) (2 bps)
Building audio filter chain for 44100Hz/2ch/16bit -> 44100Hz/2ch/16bit...
Starting playback...
VDec: vo config request - 720 x 360 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 2.43:1 - prescaling to correct movie aspect.
VO: [xv] 720x360 => 874x360 Planar YV12
New_Face failed. Maybe the font path is wrong. 1 0% 0% 0.0% 0 0 0%
Please supply the text font file (~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.

Could it just be that I just have to specify a different bitrate for the audio?

Well this line indicates that you're using OSS emulation so maybe that's the problem. Try the -ao alsa1x option or -ao help for a list of available audio outputs.

Doubtful. Only if this is the sole file that causes trouble... and even then only maybe.

I noticed something else which may not have any effect but is generally benficial:
This line indicates that you're not using linux hardware real time clock. This can cause a few problems here and there. You could try running mplayer as root. Or try executing the line (as root) echo 1024 > /proc/sys/dev/rtc/max-user-freq and then running mplayer (not as root).

This may not be the best file to check mplayer's workability since it looks a little broken.