Disappointing CVD quality. Actual bitrate much lower than preset bitrate

[Mildew]

I read the gushing CVD guide here at videohelp.com, and I was intrigued by the supposed advantages of the CVD format.

The ffmpegX CVD preset gives a video bitrate of 2300 kbit/s, which is pretty close to the guide's recommedations:

- Top quality can be expected with CBR up to 2520kb/s. You get 35-38 min per CD, and it is near DVD quality.

However, the CVDs I've encoded from XVID .avis haven't been nearly as good as SVCDs from the same files. I encoded them at 2300 kbit/sec (CBR). I checked the bitrates of the resulting CVDs and discovered that they're only 1658 kbit/sec.

Now, I still have a lot to learn about video encoding and resolutions and interlacing, etc., but it seems to me that the CVD should've had a bitrate of 2300 kbit/s because I encoded it using CBR, not VBR.

Does anyone know why the bitrate of my CVDs don't match the bitrate in the CVD preset? Did I do something wrong? Or is ffmpegX malfunctioning?

Also, if I click "Best" in the bitrate calculator, it gives me a video bitrate of 1831 kbit/sec. Again, this is far from the recommended 2520 kb/s high quality bitrate.

[major]

mpeg2enc should output the specified bitrate, did you make sure that prior to encoding the video bitrate field was indicating 2300 and not 1800 kbps?

[Mildew]

mpeg2enc should output the specified bitrate, did you make sure that prior to encoding the video bitrate field was indicating 2300 and not 1800 kbps?

Yes, definitely.

I checked the CVD in MPEG Streamclip ("Show Stream Info") and this is what it shows:

Duration: 0:44:36
Data Size: 539.85 MB
Bit Rate: 1.69 Mbps

Video Tracks:
224 MPEG-2, 352 × 576, 4:3, 25 fps, 2.30 Mbps, upper field first

Audio Tracks:
192 MP2 stereo, 48 kHz, 224 kbps

And ffmpegX shows a "muxrate" of 2.58 Mbps.

[major]

I'll look into it more closely with a bitrate analyzer.

[Mildew]

I'll look into it more closely with a bitrate analyzer.

I reverted to the old binaries and the problem still exists.

Also, the problem only exists with the mpeg2enc (mpeg-2) encoder. I tried SVCD (mpeg2enc) and the actual bitrate was just under 2000 kbit/s instead of the setting of 2500 kbit/s. The ffmpeg engine generates the correct bitrate, as does the VCD (mpeg2enc) preset.

[Mildew]

I'll look into it more closely with a bitrate analyzer.

Have you had a chance to check out this issue?