This video can't be played

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• This isn't a feature request or a discussion topic

Bug description

Video of an app window recorded on a Windows PC using OBS fails to play on IOS (works on PC and Android).

Video encoding details:

General
Complete name                            : D:\Recordings\2026-08-06 13-46-40.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/mp41)
File size                                : 3.07 MiB
Duration                                 : 27 s 350 ms
Overall bit rate mode                    : Variable
Overall bit rate                         : 943 kb/s
Writing application                      : Lavf62.12.102

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main@L3.1@Main
Codec ID                                 : hev1
Codec ID/Info                            : High Efficiency Video Coding
Duration                                 : 27 s 350 ms
Source duration                          : 27 s 300 ms
Bit rate                                 : 886 kb/s
Maximum bit rate                         : 10 000 kb/s
Width                                    : 804 pixels
Height                                   : 478 pixels
Display aspect ratio                     : 5:3
Frame rate mode                          : Constant
Frame rate                               : 60.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Bits/(Pixel*Frame)                       : 0.038
Stream size                              : 2.89 MiB (94%)
Source stream size                       : 2.99 MiB (97%)
Color range                              : Full
Color primaries                          : BT.709
Transfer characteristics                 : sRGB/sYCC
Matrix coefficients                      : BT.709
mdhd_Duration                            : 27367
Codec configuration box                  : hvcC

Audio #1
ID                                       : 2
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 27 s 264 ms
Source duration                          : 27 s 285 ms
Bit rate mode                            : Variable
Bit rate                                 : 2 274 b/s
Maximum bit rate                         : 256 kb/s / 256 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 7.57 KiB (0%)
Source stream size                       : 7.58 KiB (0%)
Title                                    : Desktop Audio
Default                                  : Yes
Alternate group                          : 1

Audio #2
ID                                       : 3
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 27 s 264 ms
Source duration                          : 27 s 285 ms
Bit rate mode                            : Variable
Bit rate                                 : 2 274 b/s
Maximum bit rate                         : 256 kb/s / 256 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 7.57 KiB (0%)
Source stream size                       : 7.58 KiB (0%)
Title                                    : VOIP Audio
Default                                  : No
Alternate group                          : 1

Audio #3
ID                                       : 4
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 27 s 264 ms
Source duration                          : 27 s 285 ms
Bit rate mode                            : Variable
Bit rate                                 : 2 274 b/s
Maximum bit rate                         : 256 kb/s / 256 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 7.57 KiB (0%)
Source stream size                       : 7.58 KiB (0%)
Title                                    : MIC Audio
Default                                  : No
Alternate group                          : 1

Steps to reproduce

• Record a video with settings like the ones above
• Share it with yourself from Windows PC Signal version
• Try playing it on IOS Signal app

Actual result: Video displays a square with play symbol and a slash drawn over it. Tapping it shows the message "This video can't be played" at the bottom of the app window.

Expected result: Video should display preview and play normally.

Screenshots

Device info

Device: iPhone 16 Pro Max

iOS version: 26.6

Signal version: 8.22 (1774)

Link to debug log

Start by reproducing the Windows-to-iOS sharing flow with an HEVC MP4 matching the reported encoding details, then trace the iOS video playback entry point. No source file or test is named in the report, and the debug-log link is missing. Done means the shared video shows a preview and plays normally on the reported iOS configuration.