Sur d’autres sites (7590)

• Modify H.264 Level in MP4 stream

  25 mars 2013, par d33pika

  I have 1000+ videos with wrong Level information, and hence do not play on some devices. They are H.264 baseline with aac audio in mp4 container. I want to correct them but avoid re-encoding. Am I right in assuming that this is possible and will be faster ? How do I identify the level_idc bits in the streams ? Will all streams have them in the same location ? I expect this to be in just one place in the stream, is this assumption correct ?
  Update : I came across a windows executable link that claims to do this. I want to be able to do this commandline on unix, so I can script it.

  More Updates : As per Roman's answer below. I dug up MP4 syntax and found that Profile and Level information are part of avcC atom under stsd. I could see that level was set to 1E, I corrected it to 1F. Before :

  61 76 63 43 01 42 C0 1E FF E1 00 19 67 42 C0 1E
D9

  After :

  61 76 63 43 01 42 C0 1F FF E1 00 19 67 42 C0 1E
D9

  with that the MediaInfo changed to :

  Video
  
  ID                                       : 1
  
  Format                                   : AVC
  
  Format/Info                              : Advanced Video Codec
  
  Format profile                           : Baseline@L3.0
  
  Format settings, CABAC                   : No
  
  Format settings, ReFrames                : 3 frames
  
  Muxing mode                              : Container profile=Baseline@3.1
  
  Codec ID                                 : avc1
  
  Codec ID/Info                            : Advanced Video Coding
  
  Duration                                 : 1mn 4s
  
  Bit rate                                 : 3 000 Kbps
  
  Width                                    : 1 280 pixels
  
  Height                                   : 720 pixels
  
  Display aspect ratio                     : 16:9
  
  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)                       : 0.109
  
  Stream size                              : 22.7 MiB (92%)
  
  Writing library                          : x264 core 120 r2151 a3f4407
  
  Encoding settings                        : cabac=0 / ref=3 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=0 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=abr / mbtree=1 / bitrate=3000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 

  It introduced a Muxing mode parameter with level 3.1 but alas this stream did not play on the device either. How do I correct the level indicated in Format Profile Is this possible without re-encoding ?

• FFmpeg h264_v4l2m2m encoder changing aspect ratio from 16:9 to 1:1 with black bars

  8 janvier, par LycoReco2007

  When switching from libx264 to h264_v4l2m2m encoder in FFmpeg for YouTube streaming, the output video's aspect ratio changes from 16:9 to 1:1 with black bars on the sides, despite keeping the same resolution settings.

  


  Original working command (with libx264) :

  


  ffmpeg -f v4l2 \
    -input_format yuyv422 \
    -video_size 1280x720 \
    -framerate 30 \
    -i /dev/video0 \
    -f lavfi \
    -i anullsrc=r=44100:cl=stereo \
    -c:v libx264 \
    -preset ultrafast \
    -tune zerolatency \
    -b:v 2500k \
    -c:a aac \
    -b:a 128k \
    -ar 44100 \
    -f flv rtmp://a.rtmp.youtube.com/live2/[STREAM-KEY]


  


  When I replaced libx264 with h264_v4lm2m, it always produce a square resolution, and it automatically adds black bars to the top and the bottom of the sides of the camera. I currently using a Rasberry Pi 4 model B, with a webcam that I believe supports the 16:9 ratio (I've verified using v4l2-ctl --list-formats-ext -d /dev/video0 command)

  


  I've tried the follows :

  


  

  • Adding -aspect 16:9 parameter in the ffmpeg command

  


  • Adding video filters such as -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2,setsar=1"
None of these give me the correct aspect ratio.

  


  


  How can I make the h264_v4l2m2m encoder maintain the original 16:9 aspect ratio without adding black bars ? Is this a known limitation of the encoder, or am I missing some required parameters ?

  


• Editing Caption in Video Message Changes Aspect Ratio to Square

  12 octobre 2024, par Shayki Abramczyk

  I'm working on a Telegram bot that processes videos by adding a watermark and then edits the original message to replace the video in a channel post. The issue I'm encountering is that when I edit the message with the new video, the aspect ratio changes, and the video becomes a square, even though the original video is in vertical format.

  


  Here’s a simplified version of the code I’m using to edit the message with the processed video :

  


  video_file = await video.get_file()
print(video_file)
random = randint(0,9999)
input_path = f"input_{user_id}_{random}.mp4"
output_path = f"output_{user_id}_{random}.mp4"
await video_file.download_to_drive(input_path)

loop = asyncio.get_event_loop()
executor = ThreadPoolExecutor()
await loop.run_in_executor(executor, process_video_sync, input_path, output_path, watermark_path, settings)

try:
    if return_file:
        return open(output_path, 'rb')
    if channel:
        chat_id = post.chat_id
        message_id = post.message_id
        caption = post.caption if post.caption else ""
        if settings['has_signature']:
            signature = settings['signature']
        else:
            caption = post.caption_html if post.caption_html else (post.caption or "")
        video_clip = VideoFileClip(output_path)
        await context.bot.edit_message_media(
            chat_id=chat_id,
            message_id=message_id,
            media=InputMediaVideo(media=open(output_path, 'rb'), width=video_clip.w, height=video_clip.h, caption=caption, parse_mode="HTML")
        )
    elif update.message:
        caption = update.message.caption if update.message.caption else ""
        video_clip = VideoFileClip(output_path)
        
        with open(output_path, 'rb') as video_file:
            await update.message.reply_video(
                video=InputFile(video_file),
                caption=caption,
                width=video_clip.w,
                height=video_clip.h,
                supports_streaming=True
            )
except Exception as e:
    logger.error("Error in sending video. Exception Type:", e.args[0][0], "Message:", e.args[0][1])
finally:
    os.remove(input_path)
    os.remove(output_path)


  


  When editing the message in a channel, the video’s aspect ratio changes from vertical to square (if the video is horizonal it's ok). However, if I send the video as a new message, the aspect ratio remains correct.

  


  How can I ensure that when I edit the video in the channel, the aspect ratio stays the same as the original, and doesn’t get cropped or turned into a square ?

  


  EDIT :

  


  I found it's because I editing the video caption and added there some HTML elements which cause it.

  


  If I just add a simple text it's ok.

  


  Why ?