ffmpeg conversion command to output to h.264 for iPad

Question

I'm looking for a good (general) conversion command that will convert any input file to h.264 sized for the iPad.

Currently I have this command that works, that was adapted from robert.swain

With presets:

$ ffmpeg -i INPUT -acodec aac -ab 160000 -s 1024x768 -vcodec libx264 \
         -vpre slow -vpre ipod640 -b 1200kb -threads 0 -f mp4 OUTPUT.mp4

Long form, no presets:

$ ffmpeg -i INPUT -acodec aac -ab 160000 -s 1024x768 -vcodec libx264 \
         -coder 1 -flags +loop -cmp +chroma \
         -partitions +parti8x8+parti4x4+partp8x8+partb8x8 -me_method umh \
         -subq 8 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 \
         -i_qfactor 0.71 -b_strategy 2 -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 \
         -bf 3 -refs 5 -directpred 3 -trellis 1 \
         -flags2 +bpyramid+mixed_refs+wpred+dct8x8+fastpskip -wpredp 2 \
         -rc_lookahead 50 -coder 0 -bf 0 -refs 1 -flags2 -wpred-dct8x8 \
         -level 30 -maxrate 10000000 -bufsize 10000000 -wpredp 0 -b 1200k \
         -threads 0 -f mp4 OUTPUT.mp4

Note: I'm skipping the aspect ratio because we handle that in the program, and we only resize it if the input resolution is greater than the output resolution.

If there's any suggestions for improvement, we are looking to balance speed, quality and conversion time.

Answer 1

Check this link. All the conversion settings you can shake a phone at. http://develop.participatoryculture.org/index.php/ConversionMatrix