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• Should H.264 bit rate be multiples of 8 ?

  31 août 2016, par Dan Sharp

  I’m working on a video platform receiving H.264 video and building an HLS stream (transmuxing the H.264 to Mpeg2 TS segments via calls to ffmpeg).

  I wanted to set the bit rate to be about 2000 kbps, but I’m wondering : does it matter if it’s 2000 or 2048 ?

  In other words, do things calculate better if the bit rate is multiples of 8, like 512 or 2024 or 2048 ?

  I don’t know enough about how the bit rate is used, either on the sending side (camera) or on the processing side (ffmpeg).

  From tests... I can’t see any noticeable difference between 2000 and 2048, but maybe one is slightly better than another for the transmuxing and segmenting ?

  I welcome any thoughts/advice.

• ffmpeg command to convert 720p to 1080p, 1440p, 2160p compatible with YouTube [closed]

  24 juin 2024, par Tendekai Muchenje

  I have a video that I created in Final Cut Pro. When i uploaded it to Youtube, it only maxes out at 720p. I would like it to have higher options like 1080, 1440 and 2160 even if the quality does not change. Maybe 2160 is impossible, but 1440p would be nice. I have tried this command, but the resulting file is unplayable, it only plays audio.

  


  ffmpeg -i Hey\ Girl.mov -vf scale=3840x2160:flags=lanczos -c:v libx264 -crf 13 -c:a aac -b:a 512k -preset slow hey_girl_hd.mov


  


  I am looking for a command that would make at least 1080 and 1440 work on YouTube. If 2160 can work, that would be great too. If it matters, here is all the info that ffprobe throws out about the file

  


  {
    "streams": [
        {
            "index": 0,
            "codec_name": "pcm_s24le",
            "codec_long_name": "PCM signed 24-bit little-endian",
            "codec_type": "audio",
            "codec_tag_string": "lpcm",
            "codec_tag": "0x6d63706c",
            "sample_fmt": "s32",
            "sample_rate": "48000",
            "channels": 2,
            "bits_per_sample": 24,
            "r_frame_rate": "0/0",
            "avg_frame_rate": "0/0",
            "time_base": "1/48000",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 8987200,
            "duration": "187.233333",
            "bit_rate": "2304000",
            "bits_per_raw_sample": "24",
            "nb_frames": "8987200",
            "disposition": {
                "default": 1,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0
            },
            "tags": {
                "creation_time": "2024-04-15T23:26:08.000000Z",
                "language": "und",
                "handler_name": "Core Media Audio",
                "vendor_id": "[0][0][0][0]"
            }
        },
        {
            "index": 1,
            "codec_name": "prores",
            "codec_long_name": "Apple ProRes (iCodec Pro)",
            "profile": "Standard",
            "codec_type": "video",
            "codec_tag_string": "apcn",
            "codec_tag": "0x6e637061",
            "width": 1280,
            "height": 720,
            "coded_width": 1280,
            "coded_height": 720,
            "closed_captions": 0,
            "has_b_frames": 0,
            "sample_aspect_ratio": "1:1",
            "display_aspect_ratio": "16:9",
            "pix_fmt": "yuv422p10le",
            "level": -99,
            "color_range": "tv",
            "color_space": "bt709",
            "color_transfer": "bt709",
            "color_primaries": "bt709",
            "field_order": "progressive",
            "refs": 1,
            "r_frame_rate": "60/1",
            "avg_frame_rate": "60/1",
            "time_base": "1/6000",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 1123400,
            "duration": "187.233333",
            "bit_rate": "138655195",
            "bits_per_raw_sample": "10",
            "nb_frames": "11234",
            "disposition": {
                "default": 1,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0
            },
            "tags": {
                "creation_time": "2024-04-15T23:26:08.000000Z",
                "language": "und",
                "handler_name": "Core Media Video",
                "vendor_id": "[0][0][0][0]",
                "encoder": "Apple ProRes 422",
                "timecode": "00:00:00:00"
            }
        },
        {
            "index": 2,
            "codec_type": "data",
            "codec_tag_string": "tmcd",
            "codec_tag": "0x64636d74",
            "r_frame_rate": "0/0",
            "avg_frame_rate": "6000/100",
            "time_base": "1/6000",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 1123400,
            "duration": "187.233333",
            "nb_frames": "1",
            "disposition": {
                "default": 1,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0
            },
            "tags": {
                "creation_time": "2024-04-15T23:26:08.000000Z",
                "language": "und",
                "handler_name": "Core Media Time Code",
                "timecode": "00:00:00:00"
            }
        }
    ],
    "format": {
        "filename": "Hey Girl.mov",
        "nb_streams": 3,
        "nb_programs": 0,
        "format_name": "mov,mp4,m4a,3gp,3g2,mj2",
        "format_long_name": "QuickTime / MOV",
        "start_time": "0.000000",
        "duration": "187.233333",
        "size": "3306875809",
        "bit_rate": "141294320",
        "probe_score": 100,
        "tags": {
            "major_brand": "qt  ",
            "minor_version": "0",
            "compatible_brands": "qt  ",
            "creation_time": "2024-04-15T23:26:08.000000Z",
            "com.apple.quicktime.keywords": "Hey GIRL",
            "com.apple.quicktime.description": "This video is about Hey Girl",
            "com.apple.quicktime.author": "Ja Mo",
            "com.apple.quicktime.displayname": "Hey Girl",
            "com.apple.quicktime.title": "Hey Girl"
        }
    }
}


  


• Different container duration between ffmpeg versions which causes audio gaps

  4 septembre 2024, par blits

  I'm trying to make a looped RTMP stream from a single video (in this
example - YouTube), but starting with version 6.0 it introduces a gap in-between loops in the audio which is quite audible. Version before 6.0 (I
tried 5.1.6 and 4.4.2) work as expected and don't introduce any gaps.

  


  The difference I spotted is that the master version (7.0.2) and the 5.1.6, for
example, report a different duration time. Is there any reason why that might happen ?

  


  v5.1.6 :

  


   Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'demo-video.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     creation_time   : 2024-09-03T15:30:51.000000Z
     encoder         : Blackmagic Design DaVinci Resolve Studio
   Duration: 00:00:05.00, start: 0.000000, bitrate: 35440 kb/s


  


  v7.0.2 :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'demo-video.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 2024-09-03T15:30:51.000000Z
    encoder         : Blackmagic Design DaVinci Resolve Studio
  Duration: 00:00:05.01, start: 0.000000, bitrate: 35346 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 2560x1440 [SAR 1:1 DAR 16:9], 35240 kb/s, 24 fps, 24 tbr, 12288 tbn (default)
      Metadata:
        creation_time   : 2024-09-03T15:30:51.000000Z
        handler_name    : VideoHandler
        vendor_id       : [0][0][0][0]
        encoder         : H.264 NVIDIA
        timecode        : 01:00:00:00


  


  As you can see, v5.1.6 report duration of 00:00:05.00 (which is correct) and v7.0.2 is 00:00:05.01 (1ms longer), which is what I think is causing the issue (but I'm not so sure about that). The original file is 5 seconds long which is what can be checked by ffprobe as well, but some streams report a 00:05.01 duration time.

  


  I tried to remedy this issue in many different ways by trimming the video/audio, using different flags, like -shortest, but that didn't help in any way - there's still a gap in the audio which is noticeable when looping the video. And like I said versions such as v5.1.6 work fine and there's no such gap.

  


  I guess what changed between versions is how ffmpeg interprets these streams but in the end I spent 2 days trying to avoid gaps in audio when streaming and nothing helped.

  


  How to reproduce :

  


  You can just stream the video in any RTMP destination of your liking, like YouTube and observe that there would be gaps (audio break-ups) in between every 5 seconds (once video ends). Video is accessible through the link from the curl command

  


  curl -o stream-audio-gap-issue.mp4 https://r2v.streamloop.app/obj_01j6y0pk83fy8vp06a9mmkkqah.mp4
ffmpeg -re -stream_loop -1 -i stream-audio-gap-issue.mp4 -c copy -f flv rtmp://a.rtmp.youtube.com/live2/[your-key]


  


  Expected : there are no gaps every 5 seconds, like in old versions of ffmpeg

  


  Instead : there are tiny audio gaps which are quite noticable

  


  ffprobe outputs is available on gist : https://gist.github.com/blitss/1e221b4fa8885b1df8ac2096746239cf

  


  I'm looking for literally any workarounds that will help avoid audio gaps whilst still preserving the latest version of ffmpeg.