Recherche avancée

Sur d’autres sites (9725)

• mp4 plays only sound but no video on ios

  5 avril 2018, par Chen

  I have a video that I get from a third party provide in my App, I want to play using react-native-video. It works fine on simulator, but on a real iphone 7 it has only sound but no video.

  After further research I found, when I try to airdrop/move via itunes the video to my iphone. It shows something like the following :

  

  I have checked the codec with ffprobe and here is the output.
  ```

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'bad.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41
  
      creation_time   : 2018-03-28T21:30:13.000000Z
  
    Duration: 00:00:45.55, start: 0.000000, bitrate: 1373 kb/s
  
      Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 1042 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        creation_time   : 2018-03-28T21:30:13.000000Z
  
        handler_name    : Alias Data Handler
  
        encoder         : AVC Coding
  
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
  
      Metadata:
  
        creation_time   : 2018-03-28T21:30:13.000000Z
  
        handler_name    : Alias Data Handler
  
  [STREAM]
  
  index=0
  
  codec_name=h264
  
  codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  profile=High
  
  codec_type=video
  
  codec_time_base=1001/60000
  
  codec_tag_string=avc1
  
  codec_tag=0x31637661
  
  width=1920
  
  height=1080
  
  coded_width=1920
  
  coded_height=1080
  
  has_b_frames=1
  
  sample_aspect_ratio=1:1
  
  display_aspect_ratio=16:9
  
  pix_fmt=yuv420p
  
  level=41
  
  color_range=tv
  
  color_space=bt709
  
  color_transfer=bt709
  
  color_primaries=bt709
  
  chroma_location=left
  
  field_order=unknown
  
  timecode=N/A
  
  refs=1
  
  is_avc=true
  
  nal_length_size=4
  
  id=N/A
  
  r_frame_rate=30000/1001
  
  avg_frame_rate=30000/1001
  
  time_base=1/30000
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=1365364
  
  duration=45.512133
  
  bit_rate=1042237
  
  max_bit_rate=N/A
  
  bits_per_raw_sample=8
  
  nb_frames=1364
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:creation_time=2018-03-28T21:30:13.000000Z
  
  TAG:language=eng
  
  TAG:handler_name=Alias Data Handler
  
  TAG:encoder=AVC Coding
  
  [/STREAM]
  
  [STREAM]
  
  index=1
  
  codec_name=aac
  
  codec_long_name=AAC (Advanced Audio Coding)
  
  profile=LC
  
  codec_type=audio
  
  codec_time_base=1/48000
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=fltp
  
  sample_rate=48000
  
  channels=2
  
  channel_layout=stereo
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/48000
  
  start_pts=0
  
  start_time=0.000000
  
  duration_ts=2184582
  
  duration=45.512125
  
  bit_rate=317375
  
  max_bit_rate=458625
  
  bits_per_raw_sample=N/A
  
  nb_frames=2135
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  DISPOSITION:default=1
  
  DISPOSITION:dub=0
  
  DISPOSITION:original=0
  
  DISPOSITION:comment=0
  
  DISPOSITION:lyrics=0
  
  DISPOSITION:karaoke=0
  
  DISPOSITION:forced=0
  
  DISPOSITION:hearing_impaired=0
  
  DISPOSITION:visual_impaired=0
  
  DISPOSITION:clean_effects=0
  
  DISPOSITION:attached_pic=0
  
  DISPOSITION:timed_thumbnails=0
  
  TAG:creation_time=2018-03-28T21:30:13.000000Z
  
  TAG:language=eng
  
  TAG:handler_name=Alias Data Handler
  
  [/STREAM]

  Then I tried VLC on iOS the video played without problem (it has both video and sound), except at the beginning it shows a grey pixel screen.

  

  Next, what i did was using ffmpeg to re-encode the video stream via :

  ffmpeg -i bad.mp4 -c:a copy new.mp4

  After this new.mp4 plays with no problem.
  This is really confusing as the codec does not change and both videos works with no problem on my Mac.

  I have tried to play around with the b_frames, profile level on the new video to reproduce the problem but with no luck.

  I really do not want to process every video via ffmpeg after get it from the third party. Just wondering what might be the problem with the video ?

• poster adjustment after getting it from video

  30 juin 2016, par Jass

  I am capturing poster from this video https://www.youtube.com/watch?v=wg-kEWsL6Xc using following code. Video can be any, I am just giving example.

  shell_exec('ffmpeg -y  -itsoffset -4  -i "'.base_path().'/assets/videos/'.$file_name.'.mp4" -vcodec mjpeg -vframes 1 -an -f rawvideo -filter:v scale=1170:ih*1170/iw "'.base_path().'/assets/videos/thumbnail/'.$file_name.'.jpg"')

  Width = 1170px,

  Height= 300px (as it is background image so it does not matter)

  But I am facing adjustment problem. Following are my current views

  First : Head is cutting, here I am using css property background : url(’completepath’) center no-repeat ;
  

  Second : Showing black portion on top of head. This is the original image that I am getting from ffmpeg code.

  

  My Question : But I need image like in you tube, you can notice that in all videos we can see top portion of humans without being cutting even black portion is well adjusted.

  Currently I am downloading and testing with youtube videos but in actual job seekers will make their own videos using android/iphone or any camera and will upload on our site.

  so how i can overcome this issue means show image with proper human face and body ?

  thanks in advance.

• Playing RTP stream on Android 4.1.2 (Jelly Bean) [closed]

  27 décembre 2024, par Homie_Tomie

  I'll try to keep it quick. Using FFMPEG I started a stream on my PC. Here is the code :

  


  import subprocess

def start_stream():
    command = [
        'ffmpeg',
        '-f', 'gdigrab',  # Desktop capture (Windows)
        '-framerate', '15',  # Low framerate for higher performance
        '-i', 'desktop',  # Capture desktop
        '-c:v', 'libx264',  # Video codec (H.264)
        '-preset', 'ultrafast',  # Ultra-fast encoding preset for minimal latency
        '-tune', 'zerolatency',  # Zero latency for real-time streaming
        '-x264opts', 'keyint=15:min-keyint=15:no-scenecut',  # Frequent keyframes
        '-b:v', '500k',  # Low bitrate to minimize data usage and reduce latency
        '-s', '800x480',  # Resolution fits phone screen and helps performance
        '-max_delay', '0',  # No buffering, instant frame output
        '-flush_packets', '1',  # Flush packets immediately after encoding
        '-f', 'rtp',  # Use mpegts as the container for RTP stream
        'rtp://192.168.72.26:1234',  # Stream over UDP to localhost on port 1234
        '-sdp_file', 'stream.sdp'  # Create SDP file
    ]
    
    try:
        print("Starting stream...")
        subprocess.run(command, check=True)
    except subprocess.CalledProcessError as e:
        print(f"Error occurred: {e}")
    except KeyboardInterrupt:
        print("\nStream interrupted")

if __name__ == "__main__":
    print("Starting screen capture...")
    start_stream()


  


  Now, when I start the stream I can connect to it in VLC when I open up the stream.sdp file. Using the same method I can open up the stream on my iPhone, but when I try to open it on my old Android phone the stream connects but the screen is black. However, when I turn the screen I can see the first frame that was sent to the phone. Why does the stream not work ?

  


  I will be thankful for any and all advice :)