After video codec copy to mp4 format with ffmpeg,new video has no screen and has just audio
<p>I have an issue.sometimes when I convert video to mp4 with codec copy,my created video in chrome just has audio and it's display a black screen, and in another browsers like firefox and internet explorer video doesn't play.
but I check this created video on my server and video displays.
<br>And here is my code in below</p>

<pre><code>ffmpeg -i -f mp4 -s 123.mov -codec copy 123.mp4 
</code></pre>

<p>The Output Of ffprobe 123.mp4 is:</p>

<pre><code>Metadata:major_brand:isom
minor_version :512
compatible_brands:isomiso2mp41
encoder:Lavf57.31.100
Duration: 00:26:58.97, start: 0.000000, bitrate: 1334 kb/s
Stream #0:0(und): Video: mpeg4 (Advanced Simple Profile) (mp4v / 0x7634706D)
,yuv420p, 640x480 [SAR 1:1 DAR 4:3],1200 kb/s, 29.97 fps,29.97 tbr, 30k tbn,29.97 tbc (default)
Metadata:handler_name: VideoHandler
Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 44100 Hz, stereo, s16p, 12
7 kb/s (default)
Metadata:handler_name: SoundHandler
</code></pre>