[X10] How to get smaller MP4 output?

[Shohreh]

Hello,

I used X10 to create a webdoc file made of
- a 900MB, 1h30m WAV file
- about 100 JPG pictures*

Surprisingly, the MP4 file generated by CVS is about 950MB, ie. it's even bigger than a movie! Considering the WAV file compressed by Audacity turns out to be about 125MB and I'm just showing static JPG pictures, I would have expected the file to be about 250MB at most.

Here's the custom settings I used in CVS to compile the MP4 file:

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MPEG-4 Files
24 bits, 720 x 480, 25 fps
Frame-based
H.264 Main Profile Video: 1024 Kbps, 16:9
44100 Hz, 16 Bit, Stereo
MPEG AAC Audio: 128 Kbps

Is there something I can do to get a much smaller file?

Thank you.

* Here's more infos on the input files:

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Input #0, wav, from 'input.wav':
  Duration: 01:26:48.49, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  Duration: 01:26:48.48, start: 0.000000, bitrate: 1471 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 720x480 [SAR 40:33 DAR 20:11], 1339 kb/s, 25 fps, 25 tbr, 30k tbn, 50 tbc (default)
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)

[canuck]

You left out one very important detail: how long in time is your final mp4 video? If 90 minutes then that mp4 file is actually quite small

[Shohreh]

No, I didn't

a 900MB, 1h30m WAV file

The final MP4 is the length of the input WAV file.

Considering the WAV file can be compressed to 125MB, and the 100 JPGs weigh about 125MB as well, I would expect the MP4 output to be around 250MB, or maybe 400-500MB at most.

CVS won't let me set the X264 video bitrate to less than 1,204Mbps.

FWIW, when recompressing the MP4 output, ffmpeg turns it into a 600MB file:

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ffmpeg -i "output.mp4" -b:v 800k -c:v libx264 -pix_fmt yuv420p -c:a copy -f mp4 "output.ffmpeg.mp4"

[asik1]

Why do you think that if your audio will take 125M
Your video will take just 100M ?

When I render a JPG from samples for 10sec, I get 1.75MB file. X 6 X 90 = 945MB.

[Shohreh]

Because, like I wrote, I could compile it with Audacity, and get a good quality AAC at only 125MB.

And the JPGs taken together are about 125MB as well.

So I expected somewhere around 250MB, or maybe a bit more (400-500MB), but certainly not 900MB! I mean, a 1h30m movie is about 700MB, while I'm only using a hundred JPGs as video.

A ten-second displays means that the file should include the full picture once, and then a minuscule delta (since it's a static pic) for the next nine seconds. So even at 25fps to make it into a movie, it shouldn't be 900MB.

So it looks like CVS just won't use smaller compression :-/

[asik1]

It can use lower data rate but not for that frame size. You can always go the AVI style with XVID with much higher compresssion

[weaver]

You can upload your video to youtube and download it back ( as a privat video), the whole story will be compressed enough.

[Shohreh]

Thanks for the tip on AVI + Xvid.

Incidently, Shotcut suffers from the same issue: I always get much bigger files than when compressing with ffmpeg.

I'll give Sony Vegas a try, and see how it goes.