[vlc] Multicast streaming and CPU Usage

[Omide]

Hello

I have a small issue, I'm trying to do a multicast streaming from a TV
tuner, with the following command:

vlc -v
v4l2:///dev/video1:fps=40:tuner-frequency=161250:width=640:height=480:adev=/dev/dsp1:tuner-audio-mode=3:audio-method=2:samplerate=32000
--sout '#transcode{vcodec=mp2v, acodec=mpga,
vb=2176,ab=128,channels=2,venc=ffmpeg,aenc=ffmpeg,deinterlace}:std{access=udp,
mux=ts, dst=239.1.1.1:1234}'

The issue:
  i get image, but it's dropping frames

[0x81024c0] main mux warning: late buffer for mux input (16118)
[0x81024c0] main mux warning: late buffer for mux input (22798)
[0x81024c0] main mux warning: late buffer for mux input (18585)
[0x81024c0] main mux warning: late buffer for mux input (14113)
[0x81024c0] main mux warning: late buffer for mux input (745)
[0x81024c0] main mux warning: late buffer for mux input (3403)
[0x81024c0] main mux warning: late buffer for mux input (198291)
[0x81024c0] main mux warning: late buffer for mux input (25495)
[0x81024c0] main mux warning: late buffer for mux input (31921)
[0x81024c0] main mux warning: late buffer for mux input (167900)

and cpu usage it's 90-100%

 cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Pentium(R) 4 CPU 2.40GHz
stepping        : 7
cpu MHz         : 2392.078
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe up pebs bts
cid
bogomips        : 4789.74
clflush size    : 64
power management:

WHY?

What is wrong?
What is the minimal configuration(cpu, mem) for this?

thx