iOS: AVPlayer shows black screen and can't play some mp4 videos

Question

I am using AVPlayer in AVFoundation to play mp4 videos in my app. Mostly the player is ok. But these two days i meet a .mp4 file that the player couldn't play. It shows black screen but no any pictures. I am very confused. Here is the metadata of the .mp4 file.

General
Complete name                    : E:\test.mp4
Format                           : MPEG-4
Format profile                   : Base Media
Codec ID                         : isom
File size                        : 28.2 MiB
Duration                         : 1mn 30s
Overall bit rate                 : 2 613 Kbps
Encoded date                     : UTC 2015-01-09 13:55:04
Tagged date                      : UTC 2015-01-09 13:55:04

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : High@L4.1
Format settings, CABAC           : Yes
Format settings, ReFrames        : 1 frame
Muxing mode                      : Container profile=High@1.3
Codec ID                         : avc1
Codec ID/Info                    : Advanced Video Coding
Duration                         : 1mn 27s
Bit rate mode                    : Variable
Bit rate                         : 2 675 Kbps
Width                            : 756 pixels
Height                           : 1 260 pixels
Display aspect ratio             : 0.600
Frame rate mode                  : Variable
Frame rate                       : 54.536 fps
Minimum frame rate               : 4.646 fps
Maximum frame rate               : 148.515 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.051
Stream size                      : 27.9 MiB (99%)
Title                            : VideoHandle
Language                         : English
Encoded date                     : UTC 2015-01-09 13:55:04
Tagged date                      : UTC 2015-01-09 13:55:04

Audio
ID                               : 2
Format                           : AMR
Format/Info                      : Adaptive Multi-Rate
Format profile                   : Narrow band
Codec ID                         : samr
Duration                         : 1mn 30s
Bit rate mode                    : Constant
Bit rate                         : 12.8 Kbps
Channel(s)                       : 1 channel
Sampling rate                    : 8 000 Hz
Bit depth                        : 13 bits
Stream size                      : 141 KiB (0%)
Title                            : SoundHandle
Writing library                  :    
Language                         : English
Encoded date                     : UTC 2015-01-09 13:55:04
Tagged date                      : UTC 2015-01-09 13:55:04

Answer 1

Just as an addendum to this, one reason why mp4 files sometimes do not play in AVPlayer comes down to one checkbox.

When you drag/drop to add the video file to your XCode project, a panel drops down with some options. One of those options is "Add to targets:".

from XCode: dragging and dropping a video file

With .MOV files you do not need to check this checkbox. With all other file formats you do need to check this checkbox.

So, maybe if you are like me you spend, oh, a day or so, probing into AVAsset and so forth trying to work out why the file doesn't seem to be loading.

That's the answer. The checkbox. Only mp4, not MOV.

Because, Apple.

Answer 2

I found a solution finally. After setting the videoCompostion of the avplayerItem, it works. The content of the videoComposition is actually the same of the video. So it is playing the preview composition in the memory but not the video file. It is a trick. However I still don't know why the avplayer shows the black screen.