Mythtv transcode for Android – Adamish

After a number of issues with avconv I switched to ffmpeg. Out of memory (OOM) errors. Non-monotonic timestamp issues, and audio/video sync problems
Sometimes mythtranscode can fail. If it does, the recommended way to fix it is to stream copy the .mpg using ffmpeg, replace the original file and try again.
Android only supports H264 baseline profiles.
480p works quite nicely on a Samsung S3 screen
Built-in mythtv editor for cut-points easy and quick to use – in conjunction with “honorcutlist” option.

Custom job command to invoke

/home/mythtv/bin/transcode.sh "%DIR%/%FILE%" "%TITLE%" "%SUBTITLE%" "%STARTTIMEUTC%" %CHANID%

Script

#!/bin/bash

file="$1"
title=$(echo $2 |  tr -c "[^A-Za-z0-9]" "." )
subtitle=$(echo $3 |  tr -c "[^A-Za-z0-9]" "." )
date=$(echo $4 | perl -pe 's/(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})/\1.\2.\3-\4.\5/')
nice_title="$title-$subtitle-$date"

DEST="$(dirname $file)/phone"
mkdir -p $DEST

WORKING="$(dirname $file)/working"
mkdir -p $WORKING
cd $WORKING

if [ -f "$DEST/$nice_title.mp4" ]; then
  echo "$DEST/$nice_title.mp4 already exists. Exiting"
  exit
fi

mythtranscode --mpeg2 --chanid $5 --starttime $4 --honorcutlist
if [ ! "$?" == "0" ]; then
 echo "Transcode failed. Attempting to fix with stream copy"
 $HOME/bin/ffmpeg -i $1 -acodec copy -vcodec copy $1.fixed.mpg
 mv $1 $1.backup
 mv $1.fixed.mpg $1
 mythtranscode --mpeg2 --chanid $5 --starttime $4 --honorcutlist
fi;
 
$HOME/bin/ffmpeg -y -i $1.tmp \
 -c:v libx264 -preset slower -profile:v baseline \
 -strict experimental -c:a libfdk_aac -b:a 96k \
 -vf yadif,scale="trunc(oh*a/2)*2:480" -crf 23 -r 25 \
 "$nice_title.mp4"

mv -f "$nice_title.mp4" $DEST

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