Transcode Video
How to transcode video for iPod, iPhone, PSP, PDA, or other portable devices. There are a lot of different ways to transcode video for use on portable devices, both automated and manually. Some of these methods may be out of date and no longer work.
Contents
nuvexport
nuvexport is a utility that can be run from the commandline. You select the output format, the videos you'd like to transcode, and it does it for you. It does not automatically transcode for you, however
See Nuvexport.
mythtranscode
mythTV can automatically transcode videos after recording them using mythtranscode. It can only transcode to RTJPEG and MPEG4, however, which may not be what your device requires.
See Mythtranscode.
Mythbrake
Mythbrake is a user job script that transcodes recordings to MP4 files using Handbrake. It can create multilanguage files with mutliple audio tracks. It automatically preserves any surround sound (e.g. AC3 5.1) using pass-through if available.
See Mythbrake.
mythnuv2mkv
See Mythnuv2mkv.
nuv2avi
See Nuv2avi.
3gp Video
Transcoding video to 3gp format for mobile phones
See Transcoding into a 3gp Video.
video2ipod
a perl script that can be installed as a User-Job to automatically transcode video for the iPod. May work for other portable devices as well.
http://wiki.1.jeffornot.com:8000/index.php/Video2ipod
Other iPod exporting Scripts
Here are some alternatives to video2ipod
- Ipod_export - Perl script with lots of options
- http://en.gentoo-wiki.com/wiki/TIP_MythTV_to_iPod (probably deprecated, uses nuvexport)
OTA HDTV to DVD with AC3 stream copy transcode Script
#!/bin/sh # Step 1, generate DVD resolution file from HDTV content, preserving AC3 audio streams # produce less log output with the -quiet switch /usr/bin/nice -19 /usr/bin/mencoder -quiet -oac copy -of mpeg \ -mpegopts format=dvd:tsaf -vf scale=720:-3,harddup -ovc lavc -lavcopts \ vcodec=mpeg2video:vbitrate=4000:keyint=15 /myth/tv/$1 -o /myth/tv/$1.tmp if [ "$?" -ne "0" ]; then echo "mencoder died" /usr/bin/nice -19 rm /myth/tv/$1.tmp exit fi # Step 2, replace orig HDTV file with transcoded DVD file /usr/bin/nice -19 mv /myth/tv/$1.tmp /myth/tv/$1 # Step 3, clean up MPEG2 sync issues and using mythtranscode. Output is a .tmp file. /usr/bin/nice -19 /usr/bin/mythtranscode --mpeg2 -i /myth/tv/$1 --showprogress # Step 4, replace DVD file with cleaned DVD file /usr/bin/nice -19 mv /myth/tv/$1.tmp /myth/tv/$1 # Step 5, update index in database /usr/bin/nice -19 /usr/bin/mythcommflag --rebuild -f /myth/tv/$1 # OPTIONAL Step 6, Flag commercials on final file /usr/bin/nice -19 /usr/bin/mythcommflag -f /myth/tv/$1 #Only thing to sort out is updating the MySQL DB for the new filesize after transcoding # to reflect the new file size. Any ideas on how to do this easily?? # ANSWER: # You can do something like this: SIZE=`ls -l $MYTHDIR/$1 | awk '{print $5}'` mysql --user=(your username) --password=(your password) mythconverg << EOF update recorded set filesize = '$SIZE' where basename = '$1'; EOF
Handbrake_userjob
The Handbrake_userjob is a perl script which is intended to run as user job. It creates .mkv (matroska) files with multilanguage audio tracks. Audio tracks are selected by language, amount of channels (5.1 > 2.0) and codec (ac3, mp2, ..). Uses new (0.25) feature of season / episode info to form video filename with the scheme: TITLE - SxxExx - SUBTITLE.mkv
See Handbrake_userjob.
avconv
This is a very simple procedure to transcode a video for display on a phone. It does not skip advertisements.
Make sure the program avconv is available
which avconv /usr/bin/avconv
Otherwise, install it. In ubuntu:
sudo apt-get install libav-tools
In mythfrontend, navigate Media Library -> Watch Recordings and browse to the recording you want to transfer. Type "i" to bring up Program Details. Note the Recorded File Name, e.g. 1833_201406281100000000.mpg. Hit <esc> to close Program Details.
Remove the uSDHC card from your phone. Connect it to the computer's USB port with a suitable adaptor, and identify the device:
sudo fdisk -l|grep FAT /dev/sdc1 8192 61405183 30698496 c W95 FAT32 (LBA)
Mount the disk:
sudo mount /dev/sdc1 /mnt
cd to /var/lib/mythtv/recordings and confirm the file is present:
cd /var/lib/mythtv/recordings /var/lib/mythtv/recordings# ls 1833_20140628110000.mpg 1833_20140628110000.mpg
Transcode and copy to the card in one step:
sudo avconv -i 1833_201406281100000000.mpg -strict experimental "/mnt/music/The Movie Title.mp4"
On my phone (Samsung Galaxy S4) the Video Player or MX Video apps can display an MP4 file. Your phone may take something different. The video I got was very low resolution.
Use mediainfo (from the Ubuntu "mediainfo" package) to display the details about a video file. Here's part of the listing for the original Myth recording:
$ mediainfo 1833_20140628110000.mpg General ID : 0 (0x0) Complete name : 1833_20140628110000.mpg Format : MPEG-TS File size : 12.4 GiB Duration : 1h 59mn Overall bit rate mode : Variable Overall bit rate : 14.8 Mbps Video ID : 1984 (0x7C0) Menu ID : 1 (0x1) Format : MPEG Video Format version : Version 2 ... Duration : 1h 59mn Bit rate mode : Variable Bit rate : 13.2 Mbps Maximum bit rate : 20.0 Mbps Width : 1 920 pixels Height : 1 080 pixels Display aspect ratio : 16:9 ... Stream size : 11.0 GiB (89%) Audio #1 ID : 1985 (0x7C1) Menu ID : 1 (0x1) Format : AC-3 Format/Info : Audio Coding 3 Mode extension : CM (complete main) Codec ID : 129 Duration : 1h 59mn Bit rate mode : Constant Bit rate : 448 Kbps Channel(s) : 6 channels ...
The transcoding using the above command line had a video bit rate of only 2 Mbps. I improved the video greatly by increasing the video bit rate to 8 Mbps like this:
sudo avconv -i 1833_201406281100000000.mpg -b:v 8M -strict experimental "/mnt/music/The Movie Title.mp4"
However, the output file was larger than the maximum permitted (about 4GB) by the FAT filesystem on the uSDHC card, so I split the movie into three segments of one hour each. The -ss option specifies the start point, and the -t specifies the duration, both in hours:minutes:seconds notation.
sudo avconv -i foo.mpg -t 01:01:00 -b:v 8M -strict experimental /mnt/foo_1.mp4 sudo avconv -ss 01:00:00 -i foo.mpg -t 01:02:00 -b:v 8M -strict experimental /mnt/foo_2.mp4 sudo avconv -ss 02:00:00 -i foo.mpg -b:v 8M -strict experimental /mnt/foo_3.mp4
The one or two minute overlap allows for some inaccuracy in seeking to the starting point.
Transcoding takes a while. Over the air video normally runs at 30 frames per second, so if avconv displays "fps=60" then transcoding will take half the running time of the video. If you have a multicore system, you may want to open another terminal window and start a second transcoding job that can run in parallel.
When jobs are finished, unmount the disk:
sudo umount /mnt