# Extracts FLV files (Flash Video).
# Contributed by John Zoidberg <zohn.joidberg@gmail.com>
# Depends on MPlayer's mencoder: http://www.mplayerhq.hu/

0 string FLV\x01

#4 int32 05000000 ffffffff
4 int32 00000000 f0ffffff
8 int32 09000000 ffffffff
12 int32 00000000 ff000000

extension flv

# mencoder will keep reading after the flv ends, so we use tools/safecat to
# stop it when it's not outputting useful things anymore.
command safecat -d 30M -u 200M -t 200M "$1" | mencoder -of lavf -nocache -o "$1" -ovc copy -oac copy -

min_output_file 102400

# A few notes about the recipe:
# 1) It is based on the official FLV file specification from
# http://www.adobe.com/devnet/flv/
# 2) I assume FLV version 1 + audio tags present + video tags present
# 
# This leads to a header of the form
# # header
# # 46 4C 56 01  05 00 00 00  09
# # header + start of file body
# # 46 4C 56 01  05 00 00 00  09 00 00 00  00
# 
# However, I found some FLV files which started like this instead:
# # 46 4C 56 01  0D 00 00 00  09 00 00 00  00
# 0D=00001101 is contrary to the official file specification.
# Only 00,01,04 or 05 should be possible.