[Ffmpeg-devel] ffmpeg mp4 demuxer doesnt handle 64bit
bond
b-o-n-d
Fri Dec 30 12:48:06 CET 2005
the ffmpeg mp4 demuxer doesnt seem to handle 64bit values in the mp4
headers, as allowed by the specs
whenever i try to play such a file mplayer by using the ffmpeg demuxer
via -demuxer 35 it tells me "LAVF: no audio or video headers found - broken
file?" obviously the headers are there and all other players i tried handle
the file fine
i assume thats caused as in the mdhd atom, which stores the timescale and
the duration, the creation/modification time is also set as 64bit, which
leads to that the demuxer thinks the followup timescale is zero, which might
lead to the error above
i have tried uploaded a file showing this to the mplayer ftp (incoming) but
access was denied
anyways attached the structure of the mdhd atom:
type mdia
type mdhd
version = 1 (0x01)
flags = 0 (0x000000)
creationTime = 3218293987 (0x00000000bfd344e3)
modificationTime = 3218295051 (0x00000000bfd3490b)
timeScale = 15712911 (0x00efc28f)
duration = 4525654016 (0x000000010dc00000)
language = 21956 (0x55c4)
reserved = <2 bytes> 00 00
the version = 1 flag indicates that 64bit is used, it seems mplayer ignores
this and thinks 32bit is used always. 64bit is allowed as can be seen in the
specs on page 20:
http://standards.iso.org/ittf/PubliclyAvailableStandards/c042292_ISO_IEC_14496-12_2005_Cor_1_2005(E).zip
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