TimeSpan overflow in QuickTimeMetadataReader (with bad MP4 file)
kirk-marple opened this issue · comments
Ran across this recently, and just wanted to post this for awareness.
In ReadMetadata, if the timeScale comes back as zero (because of bad header data), this can cause a divide by zero error, and overflow creating the TimeSpan.FromSeconds.
I have a file from 2017, taken on a Samsung Android phone. I'm guessing they had a bug in their MP4 writer back then.
The created and modified dates that are parsed are bogus (like 1908 for created date).
Line 249:
directory.Set(QuickTimeMovieHeaderDirectory.TagCreated, _epoch.AddTicks(TimeSpan.TicksPerSecond * a.Reader.GetUInt32()));
directory.Set(QuickTimeMovieHeaderDirectory.TagModified, _epoch.AddTicks(TimeSpan.TicksPerSecond * a.Reader.GetUInt32()));
var timeScale = a.Reader.GetUInt32();
directory.Set(QuickTimeMovieHeaderDirectory.TagTimeScale, timeScale);
directory.Set(QuickTimeMovieHeaderDirectory.TagDuration, TimeSpan.FromSeconds(a.Reader.GetUInt32() / (double)timeScale));
Here's the MediaInfo output from it:
General
Complete name : C:\Users\kirk\Pictures\Austin\20161126_132809.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
File size : 9.13 MiB
Duration : 9 s 380 ms
Overall bit rate mode : Variable
Overall bit rate : 8 166 kb/s
Tagged date : UTC 2016-11-27 01:07:53
xyz : +30.2627-097.9380/
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 1 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 1 frame
Format settings, GOP : M=1, N=60
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 9 s 333 ms
Bit rate : 8 010 kb/s
Maximum bit rate : 9 410 kb/s
Width : 1 080 pixels
Height : 1 920 pixels
Display aspect ratio : 0.563
Frame rate mode : Constant
Frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.129
Stream size : 8.91 MiB (98%)
Tagged date : UTC 2016-11-27 01:07:54
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC
Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 9 s 380 ms
Bit rate mode : Variable
Bit rate : 192 kb/s
Maximum bit rate : 203 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 220 KiB (2%)
Title : IsoMedia File Produced by Google, 5-11-2011
Language : English
Encoded date : UTC 2016-11-27 01:07:53
Tagged date : UTC 2016-11-27 01:07:54
Hey Kirk. Are you able to provide that sample file?
I believe that PR fixes it, but cannot verify that the resulting duration value makes any sense. It'd be great to have a test file.
@drewnoakes Here you go. Enjoy the tortoises :)
#270 fixed the exception, but the resulting value is garbage:
[QuickTime Movie Header - 0x0006] Duration = 41239.01:07:53
Java produces more sensible values here. We should compare the behaviour of both to understand the difference.