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Somos millones 1
21 juillet 2014, par
Mis à jour : Juin 2015
Langue : français
Type : Video
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Participer à sa traduction
10 avril 2011Vous pouvez nous aider à améliorer les locutions utilisées dans le logiciel ou à traduire celui-ci dans n’importe qu’elle nouvelle langue permettant sa diffusion à de nouvelles communautés linguistiques.
Pour ce faire, on utilise l’interface de traduction de SPIP où l’ensemble des modules de langue de MediaSPIP sont à disposition. ll vous suffit de vous inscrire sur la liste de discussion des traducteurs pour demander plus d’informations.
Actuellement MediaSPIP n’est disponible qu’en français et (...) -
Use, discuss, criticize
13 avril 2011, parTalk to people directly involved in MediaSPIP’s development, or to people around you who could use MediaSPIP to share, enhance or develop their creative projects.
The bigger the community, the more MediaSPIP’s potential will be explored and the faster the software will evolve.
A discussion list is available for all exchanges between users. -
Support audio et vidéo HTML5
10 avril 2011MediaSPIP utilise les balises HTML5 video et audio pour la lecture de documents multimedia en profitant des dernières innovations du W3C supportées par les navigateurs modernes.
Pour les navigateurs plus anciens, le lecteur flash Flowplayer est utilisé.
Le lecteur HTML5 utilisé a été spécifiquement créé pour MediaSPIP : il est complètement modifiable graphiquement pour correspondre à un thème choisi.
Ces technologies permettent de distribuer vidéo et son à la fois sur des ordinateurs conventionnels (...)
Sur d’autres sites (8172)
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Python : Extracting device and lens information from video metadata
14 mai 2023, par cat_got_my_tongueI am interested in extracting device and lens information from videos. Specifically, make and model of the device and the focal length. I was able to do this successfully for still images using the
exifreadmodule and extract a whole bunch of very useful information :

image type : MPO
Image ImageDescription: Shot with DxO ONE
Image Make: DxO
Image Model: DxO ONE
Image Orientation: Horizontal (normal)
Image XResolution: 300
Image YResolution: 300
Image ResolutionUnit: Pixels/Inch
Image Software: V3.0.0 (2b448a1aee) APP:1.0
Image DateTime: 2022:04:05 14:53:45
Image YCbCrCoefficients: [299/1000, 587/1000, 57/500]
Image YCbCrPositioning: Centered
Image ExifOffset: 158
Thumbnail Compression: JPEG (old-style)
Thumbnail XResolution: 300
Thumbnail YResolution: 300
Thumbnail ResolutionUnit: Pixels/Inch
Thumbnail JPEGInterchangeFormat: 7156
Thumbnail JPEGInterchangeFormatLength: 24886
EXIF ExposureTime: 1/3
EXIF FNumber: 8
EXIF ExposureProgram: Aperture Priority
EXIF ISOSpeedRatings: 100
EXIF SensitivityType: ISO Speed
EXIF ISOSpeed: 100
EXIF ExifVersion: 0221
EXIF DateTimeOriginal: 2022:04:05 14:53:45
EXIF DateTimeDigitized: 2022:04:05 14:53:45
EXIF ComponentsConfiguration: CrCbY
EXIF CompressedBitsPerPixel: 3249571/608175
EXIF ExposureBiasValue: 0
EXIF MaxApertureValue: 212/125
EXIF SubjectDistance: 39/125
EXIF MeteringMode: MultiSpot
EXIF LightSource: Unknown
EXIF Flash: Flash did not fire
EXIF FocalLength: 1187/100
EXIF SubjectArea: [2703, 1802, 675, 450]
EXIF MakerNote: [68, 88, 79, 32, 79, 78, 69, 0, 12, 0, 0, 0, 21, 0, 3, 0, 5, 0, 2, 0, ... ]
EXIF SubSecTime: 046
EXIF SubSecTimeOriginal: 046
EXIF SubSecTimeDigitized: 046
EXIF FlashPixVersion: 0100
EXIF ColorSpace: sRGB
EXIF ExifImageWidth: 5406
EXIF ExifImageLength: 3604
Interoperability InteroperabilityIndex: R98
Interoperability InteroperabilityVersion: [48, 49, 48, 48]
EXIF InteroperabilityOffset: 596
EXIF FileSource: Digital Camera
EXIF ExposureMode: Auto Exposure
EXIF WhiteBalance: Auto
EXIF DigitalZoomRatio: 1
EXIF FocalLengthIn35mmFilm: 32
EXIF SceneCaptureType: Standard
EXIF ImageUniqueID: C01A1709306530020220405185345046
EXIF BodySerialNumber: C01A1709306530


Unfortunately, I have been unable to extract this kind of info from videos so far.


This is what I have tried so far, with the
ffmpegmodule :

import ffmpeg
from pprint import pprint

test_video = "my_video.mp4"
pprint(ffmpeg.probe(test_video)["streams"])


And the output I get contains a lot of info but nothing related to the device or lens, which is what I am looking for :


[{'avg_frame_rate': '30/1',
 'bit_rate': '1736871',
 'bits_per_raw_sample': '8',
 'chroma_location': 'left',
 'codec_long_name': 'H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10',
 'codec_name': 'h264',
 'codec_tag': '0x31637661',
 'codec_tag_string': 'avc1',
 'codec_time_base': '1/60',
 'codec_type': 'video',
 'coded_height': 1088,
 'coded_width': 1920,
 'display_aspect_ratio': '16:9',
 'disposition': {'attached_pic': 0,
 'clean_effects': 0,
 'comment': 0,
 'default': 1,
 'dub': 0,
 'forced': 0,
 'hearing_impaired': 0,
 'karaoke': 0,
 'lyrics': 0,
 'original': 0,
 'timed_thumbnails': 0,
 'visual_impaired': 0},
 'duration': '20.800000',
 'duration_ts': 624000,
 'has_b_frames': 0,
 'height': 1080,
 'index': 0,
 'is_avc': 'true',
 'level': 40,
 'nal_length_size': '4',
 'nb_frames': '624',
 'pix_fmt': 'yuv420p',
 'profile': 'Constrained Baseline',
 'r_frame_rate': '30/1',
 'refs': 1,
 'sample_aspect_ratio': '1:1',
 'start_pts': 0,
 'start_time': '0.000000',
 'tags': {'creation_time': '2021-05-08T13:23:20.000000Z',
 'encoder': 'AVC Coding',
 'handler_name': 'VideoHandler',
 'language': 'und'},
 'time_base': '1/30000',
 'width': 1920},
 {'avg_frame_rate': '0/0',
 'bit_rate': '79858',
 'bits_per_sample': 0,
 'channel_layout': 'stereo',
 'channels': 2,
 'codec_long_name': 'AAC (Advanced Audio Coding)',
 'codec_name': 'aac',
 'codec_tag': '0x6134706d',
 'codec_tag_string': 'mp4a',
 'codec_time_base': '1/48000',
 'codec_type': 'audio',
 'disposition': {'attached_pic': 0,
 'clean_effects': 0,
 'comment': 0,
 'default': 1,
 'dub': 0,
 'forced': 0,
 'hearing_impaired': 0,
 'karaoke': 0,
 'lyrics': 0,
 'original': 0,
 'timed_thumbnails': 0,
 'visual_impaired': 0},
 'duration': '20.864000',
 'duration_ts': 1001472,
 'index': 1,
 'max_bit_rate': '128000',
 'nb_frames': '978',
 'profile': 'LC',
 'r_frame_rate': '0/0',
 'sample_fmt': 'fltp',
 'sample_rate': '48000',
 'start_pts': 0,
 'start_time': '0.000000',
 'tags': {'creation_time': '2021-05-08T13:23:20.000000Z',
 'handler_name': 'SoundHandler',
 'language': 'und'},
 'time_base': '1/48000'}]


Are these pieces of info available for videos ? Should I be using a different package ?


Thanks.


Edit :


pprint(ffmpeg.probe(test_video)["format"])gives

{'bit_rate': '1815244',
 'duration': '20.864000',
 'filename': 'my_video.mp4',
 'format_long_name': 'QuickTime / MOV',
 'format_name': 'mov,mp4,m4a,3gp,3g2,mj2',
 'nb_programs': 0,
 'nb_streams': 2,
 'probe_score': 100,
 'size': '4734158',
 'start_time': '0.000000',
 'tags': {'artist': 'Microsoft Game DVR',
 'compatible_brands': 'mp41isom',
 'creation_time': '2021-05-08T12:12:33.000000Z',
 'major_brand': 'mp42',
 'minor_version': '0',
 'title': 'Snipping Tool'}}


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Live video in facebook is lagging while using ffmpeg from video link
1er septembre 2022, par Isteyak AliLivevideo in facebook is working fine for local device video(case 1) but its having lagging issue from video link(case 2) using FFMPEG.


Please find command for the same and log.


Case 1 - Command : ffmpeg -re -i videoplayback.mp4 -c:v libx264 -c:a aac -f flv "rtmps ://live-api-s.facebook.com:443/rtmp/5162241770554550 ?s_bl=1&s_oil=2&s_psm=1&s_sw=0&s_tids=1&s_vt=api-s&a=Aby_ZWutqdUZR26F"


Log -
2022-09-01 18:27:19.683 frame= 9 fps=0.0 q=0.0 q=0.0 size= 0kB time=00:00:00.00 bitrate=N/A dup=21 drop=0 speed= 0x

2022-09-01 18:27:20.163 frame= 19 fps= 19 q=0.0 q=33.0 size= 0kB time=00:00:00.44 bitrate= 8.7kbits/s dup=44 drop=0 speed=0.437x

2022-09-01 18:27:20.879 frame= 32 fps= 21 q=0.0 q=33.0 size= 0kB time=00:00:00.92 bitrate= 4.1kbits/s dup=74 drop=0 speed=0.616x

2022-09-01 18:27:21.374 frame= 47 fps= 22 q=0.0 q=33.0 size= 0kB time=00:00:01.41 bitrate= 2.7kbits/s dup=109 drop=0 speed=0.651x

2022-09-01 18:27:21.940 frame= 58 fps= 21 q=29.0 q=33.0 size= 40kB time=00:00:01.90 bitrate= 174.2kbits/s dup=135 drop=0 speed=0.703x

2022-09-01 18:27:22.530 frame= 69 fps= 21 q=29.0 q=33.0 size= 101kB time=00:00:01.92 bitrate= 429.9kbits/s dup=161 drop=0 speed=0.585x

2022-09-01 18:27:23.003 frame= 83 fps= 22 q=29.0 q=33.0 size= 165kB time=00:00:02.39 bitrate= 566.5kbits/s dup=193 drop=0 speed=0.623x

2022-09-01 18:27:23.567 frame= 97 fps= 22 q=29.0 q=33.0 size= 235kB time=00:00:02.90 bitrate= 661.9kbits/s dup=226 drop=0 speed=0.667x

2022-09-01 18:27:24.133 frame= 111 fps= 23 q=29.0 q=33.0 size= 315kB time=00:00:03.36 bitrate= 765.8kbits/s dup=259 drop=0 speed=0.693x

2022-09-01 18:27:24.715 frame= 125 fps= 23 q=29.0 q=30.0 size= 385kB time=00:00:03.85 bitrate= 817.5kbits/s dup=291 drop=0 speed=0.703x

2022-09-01 18:27:25.227 frame= 142 fps= 24 q=29.0 q=33.0 size= 486kB time=00:00:04.83 bitrate= 824.6kbits/s dup=331 drop=0 speed=0.802x

2022-09-01 18:27:25.712 frame= 158 fps= 24 q=29.0 q=33.0 size= 563kB time=00:00:05.31 bitrate= 867.6kbits/s dup=368 drop=0 speed=0.811x

2022-09-01 18:27:26.262 frame= 173 fps= 24 q=29.0 q=33.0 size= 634kB time=00:00:05.78 bitrate= 897.8kbits/s dup=403 drop=0 speed=0.819x

2022-09-01 18:27:26.796 frame= 191 fps= 25 q=29.0 q=33.0 size= 718kB time=00:00:06.24 bitrate= 941.7kbits/s dup=445 drop=0 speed=0.82x

2022-09-01 18:27:27.337 frame= 211 fps= 26 q=29.0 q=33.0 size= 806kB time=00:00:07.17 bitrate= 920.7kbits/s dup=492 drop=0 speed=0.882x

2022-09-01 18:27:27.816 frame= 233 fps= 27 q=29.0 q=33.0 size= 921kB time=00:00:07.64 bitrate= 987.4kbits/s dup=543 drop=0 speed=0.881x

2022-09-01 18:27:28.348 frame= 251 fps= 27 q=29.0 q=30.0 size= 1031kB time=00:00:08.42 bitrate=1001.9kbits/s dup=585 drop=0 speed=0.919x

2022-09-01 18:27:28.868 frame= 274 fps= 28 q=29.0 q=33.0 size= 1141kB time=00:00:09.03 bitrate=1035.2kbits/s dup=639 drop=0 speed=0.933x

2022-09-01 18:27:29.393 frame= 293 fps= 29 q=29.0 q=33.0 size= 1283kB time=00:00:09.49 bitrate=1106.5kbits/s dup=683 drop=0 speed=0.932x

2022-09-01 18:27:29.870 frame= 313 fps= 29 q=29.0 q=33.0 size= 1433kB time=00:00:10.42 bitrate=1125.6kbits/s dup=730 drop=0 speed=0.975x

2022-09-01 18:27:30.356 frame= 331 fps= 30 q=29.0 q=33.0 size= 1557kB time=00:00:10.89 bitrate=1170.9kbits/s dup=772 drop=0 speed=0.973x

2022-09-01 18:27:30.843 frame= 346 fps= 30 q=29.0 q=33.0 size= 1627kB time=00:00:11.35 bitrate=1174.1kbits/s dup=807 drop=0 speed=0.971x

2022-09-01 18:27:31.357 frame= 361 fps= 30 q=29.0 q=33.0 size= 1711kB time=00:00:11.81 bitrate=1186.2kbits/s dup=842 drop=0 speed=0.969x

2022-09-01 18:27:31.862 frame= 376 fps= 30 q=29.0 q=33.0 size= 1789kB time=00:00:12.28 bitrate=1193.3kbits/s dup=877 drop=0 speed=0.967x

2022-09-01 18:27:32.371 frame= 391 fps= 30 q=29.0 q=33.0 size= 1870kB time=00:00:12.74 bitrate=1201.8kbits/s dup=912 drop=0 speed=0.965x

2022-09-01 18:27:32.908 frame= 406 fps= 30 q=29.0 q=33.0 size= 1959kB time=00:00:13.67 bitrate=1173.3kbits/s dup=947 drop=0 speed=0.997x

2022-09-01 18:27:33.109 frame= 422 fps= 30 q=29.0 q=33.0 size= 2061kB time=00:00:14.14 bitrate=1193.8kbits/s dup=984 drop=0 speed=0.992x

Case 2 - Command : ffmpeg -re -i "https://rr1---sn-o58g5ob-nu8e.googlevideo.com/videoplayback?expire=1662057728&ei=n6gQY-D9OLSA4-EPzJKYyA0&ip=103.11.117.194&id=o-AOgjPoKU_GiUy425eSSF6tHEIQvoHpsUyyIHnHERk6YS&itag=22&source=youtube&requiressl=yes&mh=6k&mm=31%2C29&mn=sn-o58g5ob-nu8e%2Csn-cvhelnls&ms=au%2Crdu&mv=m&mvi=1&pcm2cms=yes&pl=24&initcwndbps=867500&vprv=1&mime=video%2Fmp4&ns=z8jzAKb15xkjMcyG0dBthZQH&ratebypass=yes&dur=256.116&lmt=1649507860591021&mt=1662035606&fvip=3&fexp=24001373%2C24007246&c=WEB&rbqsm=fr&txp=4532434&n=PSC3ywazY86ChDwPP2&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cns%2Cratebypass%2Cdur%2Clmt&sig=AOq0QJ8wRgIhAI-aPoysSukxGNgmlsn-4bgCG84gQnILTkGJR8WQnK_bAiEArwSM0z-GYO4SinkzgdGG5qZJtoiP3ROYneg88sOjhv4%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpcm2cms%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIhAJb7JQbSPhhH2jte8pE0G0iWf1LtRlEzQgSy-2pBGPg3AiBWX0P27KU2xwazMGLiBaQanUOeytB0jPgFsJleM8DO-w%3D%3D" -c:v libx264 -c:a aac -f flv "rtmps ://live-api-s.facebook.com:443/rtmp/5162241770554550 ?s_bl=1&s_oil=2&s_psm=1&s_sw=0&s_tids=1&s_vt=api-s&a=Aby_ZWutqdUZR26F"


Log -


2022-09-01 18:24:23.080 frame= 9 fps=0.0 q=0.0 q=0.0 size= 0kB time=00:00:00.00 bitrate=N/A dup=21 drop=0 speed= 0x

2022-09-01 18:24:23.579 frame= 23 fps= 22 q=0.0 q=33.0 size= 0kB time=00:00:00.44 bitrate= 8.7kbits/s dup=53 drop=0 speed=0.427x

2022-09-01 18:24:24.177 frame= 33 fps= 21 q=0.0 q=33.0 size= 0kB time=00:00:00.92 bitrate= 4.1kbits/s dup=77 drop=0 speed=0.589x

2022-09-01 18:24:24.872 frame= 39 fps= 18 q=0.0 q=33.0 size= 0kB time=00:00:00.99 bitrate= 3.9kbits/s dup=91 drop=0 speed=0.458x

2022-09-01 18:24:25.513 frame= 46 fps= 16 q=0.0 q=33.0 size= 0kB time=00:00:01.41 bitrate= 2.7kbits/s dup=107 drop=0 speed=0.497x

2022-09-01 18:24:26.070 frame= 52 fps= 15 q=0.0 q=33.0 size= 0kB time=00:00:01.41 bitrate= 2.7kbits/s dup=121 drop=0 speed=0.41x

2022-09-01 18:24:26.602 frame= 58 fps= 14 q=29.0 q=33.0 size= 40kB time=00:00:01.90 bitrate= 174.2kbits/s dup=135 drop=0 speed=0.468x

2022-09-01 18:24:27.341 frame= 63 fps= 14 q=29.0 q=33.0 size= 72kB time=00:00:01.90 bitrate= 311.6kbits/s dup=147 drop=0 speed=0.417x

2022-09-01 18:24:27.957 frame= 71 fps= 13 q=29.0 q=33.0 size= 115kB time=00:00:02.39 bitrate= 392.6kbits/s dup=165 drop=0 speed=0.448x

2022-09-01 18:24:28.621 frame= 78 fps= 13 q=29.0 q=33.0 size= 141kB time=00:00:02.39 bitrate= 483.2kbits/s dup=182 drop=0 speed=0.409x

2022-09-01 18:24:29.277 frame= 82 fps= 12 q=29.0 q=33.0 size= 154kB time=00:00:02.39 bitrate= 527.3kbits/s dup=191 drop=0 speed=0.363x

2022-09-01 18:24:29.851 frame= 89 fps= 12 q=29.0 q=33.0 size= 197kB time=00:00:02.87 bitrate= 560.9kbits/s dup=207 drop=0 speed=0.397x

2022-09-01 18:24:30.385 frame= 96 fps= 12 q=29.0 q=33.0 size= 233kB time=00:00:02.87 bitrate= 662.2kbits/s dup=224 drop=0 speed=0.371x

2022-09-01 18:24:31.119 frame= 100 fps= 12 q=29.0 q=33.0 size= 253kB time=00:00:03.36 bitrate= 615.5kbits/s dup=233 drop=0 speed=0.402x

2022-09-01 18:24:31.449 frame= 110 fps= 12 q=29.0 q=33.0 size= 309kB time=00:00:03.36 bitrate= 750.7kbits/s dup=256 drop=0 speed=0.378x

2022-09-01 18:24:32.062 frame= 111 fps= 12 q=29.0 q=33.0 size= 315kB time=00:00:03.83 bitrate= 672.9kbits/s dup=259 drop=0 speed=0.405x

2022-09-01 18:24:32.696 frame= 122 fps= 12 q=29.0 q=33.0 size= 371kB time=00:00:03.85 bitrate= 787.6kbits/s dup=284 drop=0 speed=0.383x

2022-09-01 18:24:33.374 frame= 130 fps= 12 q=29.0 q=33.0 size= 410kB time=00:00:04.34 bitrate= 773.0kbits/s dup=303 drop=0 speed=0.407x

2022-09-01 18:24:33.987 frame= 139 fps= 12 q=29.0 q=33.0 size= 475kB time=00:00:04.34 bitrate= 895.9kbits/s dup=324 drop=0 speed=0.383x

2022-09-01 18:24:34.445 frame= 146 fps= 12 q=29.0 q=33.0 size= 508kB time=00:00:04.83 bitrate= 861.9kbits/s dup=340 drop=0 speed=0.404x

2022-09-01 18:24:35.218 frame= 153 fps= 12 q=29.0 q=33.0 size= 540kB time=00:00:05.03 bitrate= 878.1kbits/s dup=357 drop=0 speed=0.405x

2022-09-01 18:24:35.558 frame= 163 fps= 12 q=29.0 q=33.0 size= 580kB time=00:00:05.31 bitrate= 893.8kbits/s dup=380 drop=0 speed=0.408x

2022-09-01 18:24:36.220 frame= 167 fps= 12 q=29.0 q=33.0 size= 609kB time=00:00:05.31 bitrate= 938.0kbits/s dup=389 drop=0 speed=0.392x

2022-09-01 18:24:36.821 frame= 172 fps= 12 q=29.0 q=33.0 size= 630kB time=00:00:05.78 bitrate= 892.5kbits/s dup=401 drop=0 speed=0.408x

2022-09-01 18:24:37.428 frame= 179 fps= 12 q=29.0 q=33.0 size= 666kB time=00:00:05.78 bitrate= 943.1kbits/s dup=417 drop=0 speed=0.394x

2022-09-01 18:24:37.812 frame= 185 fps= 12 q=29.0 q=30.0 size= 689kB time=00:00:06.24 bitrate= 903.2kbits/s dup=431 drop=0 speed=0.41x

2022-09-01 18:24:38.368 frame= 190 fps= 12 q=29.0 q=33.0 size= 711kB time=00:00:06.24 bitrate= 932.5kbits/s dup=443 drop=0 speed=0.396x

2022-09-01 18:24:38.979 frame= 195 fps= 12 q=29.0 q=33.0 size= 737kB time=00:00:06.52 bitrate= 925.4kbits/s dup=455 drop=0 speed=0.399x

2022-09-01 18:24:39.706 frame= 204 fps= 12 q=29.0 q=33.0 size= 778kB time=00:00:06.71 bitrate= 949.8kbits/s dup=476 drop=0 speed=0.398x

2022-09-01 18:24:40.252 frame= 212 fps= 12 q=29.0 q=33.0 size= 808kB time=00:00:07.17 bitrate= 922.8kbits/s dup=494 drop=0 speed=0.407x

2022-09-01 18:24:40.977 frame= 220 fps= 12 q=29.0 q=33.0 size= 841kB time=00:00:07.17 bitrate= 960.6kbits/s dup=513 drop=0 speed=0.395x

2022-09-01 18:24:41.926 frame= 226 fps= 12 q=29.0 q=33.0 size= 886kB time=00:00:07.64 bitrate= 949.8kbits/s dup=527 drop=0 speed=0.404x

2022-09-01 18:24:42.470 frame= 233 fps= 12 q=29.0 q=33.0 size= 921kB time=00:00:07.64 bitrate= 987.4kbits/s dup=543 drop=0 speed=0.385x

2022-09-01 18:24:43.081 frame= 237 fps= 12 q=29.0 q=33.0 size= 942kB time=00:00:07.66 bitrate=1007.5kbits/s dup=553 drop=0 speed=0.374x

2022-09-01 18:24:43.745 frame= 241 fps= 11 q=29.0 q=33.0 size= 971kB time=00:00:08.10 bitrate= 981.5kbits/s dup=562 drop=0 speed=0.384x

2022-09-01 18:24:44.270 frame= 248 fps= 11 q=29.0 q=33.0 size= 1011kB time=00:00:08.10 bitrate=1021.5kbits/s dup=578 drop=0 speed=0.373x

2022-09-01 18:24:45.085 frame= 251 fps= 11 q=29.0 q=30.0 size= 1031kB time=00:00:08.10 bitrate=1042.1kbits/s dup=585 drop=0 speed=0.364x

As per my knowledge we have to add such type of delay or late stream video using some command.


-
Getting shifted timestamps when encoding a fragmented h264 mp4 with ffmpeg
14 septembre 2022, par Martin CastinI am trying to encode a fragmented h264 mp4 with ffmpeg. I tried the following command :


ffmpeg -i input.mp4 -movflags +frag_keyframe+separate_moof+omit_tfhd_offset+empty_moov output.mp4


It does give me a fragmented mp4 but the timestamps of the frames seem to be shifted by 0.04s when I read the video with mpv. The first frame has a timestamp of 0.04s instead of 0s, as in the input video (1920x1080, 50 fps). I encountered the problem both with ffmpeg 5.1 and ffmpeg 3.4.11.


I tried to add several flags, as
-avoid_negative_ts make_zeroor-copyts -output_ts_offset -0.04, but it did not help.

I am also trying to achieve this using the ffmpeg libav libraries in C++ but did not get to better result. Here are the code fragments I used.


avformat_alloc_output_context2(&oc, NULL, NULL, filename);

 if (oc_->oformat->flags & AVFMT_GLOBALHEADER) {
 codecCtx_->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
 }
...
 AVDictionary* opts = NULL;

 av_dict_set(&opts, "movflags", "frag_keyframe+separate_moof+omit_tfhd_offset+empty_moov", 0);

 ret = avformat_write_header(oc_, &opts);


Do you know how to avoid this behaviour of shifted timestamps for fragmented mp4, either with ffmpeg or libav ?


Edit : example videos and complete code example


I also tried with the following ffmpeg build


ffmpeg version 5.0.1-static https://johnvansickle.com/ffmpeg/ Copyright (c) 2000-2022 the FFmpeg developers
built with gcc 8 (Debian 8.3.0-6)
configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
libavutil 57. 17.100 / 57. 17.100
libavcodec 59. 18.100 / 59. 18.100
libavformat 59. 16.100 / 59. 16.100
libavdevice 59. 4.100 / 59. 4.100
libavfilter 8. 24.100 / 8. 24.100
libswscale 6. 4.100 / 6. 4.100
libswresample 4. 3.100 / 4. 3.100
libpostproc 56. 3.100 / 56. 3.100


and with the sintel trailer as input video, which is 24fps, and I thus get a timeshift of 83ms. Here is the output I get.


Here is a complete code example, slightly adapted from the
muxing.cffmpeg example (audio removed and adapted for c++). This code shows exactly the same problem.

You can just comment the line 383 (that is calling
av_dict_set) to switch back to a not fragmented mp4 that will not have the timestamp shift.

/*
 * Copyright (c) 2003 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * @file
 * libavformat API example.
 *
 * Output a media file in any supported libavformat format. The default
 * codecs are used.
 * @example muxing.c
 */

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cmath>

extern "C"
{
#define __STDC_CONSTANT_MACROS
#include <libavutil></libavutil>avassert.h>
#include <libavutil></libavutil>channel_layout.h>
#include <libavutil></libavutil>opt.h>
#include <libavutil></libavutil>mathematics.h>
#include <libavutil></libavutil>timestamp.h>
#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libswscale></libswscale>swscale.h>
#include <libswresample></libswresample>swresample.h>
}

#define STREAM_DURATION 10.0
#define STREAM_FRAME_RATE 25 /* 25 images/s */
#define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */

#define SCALE_FLAGS SWS_BICUBIC

// a wrapper around a single output AVStream
typedef struct OutputStream {
 AVStream *st;
 AVCodecContext *enc;

 /* pts of the next frame that will be generated */
 int64_t next_pts;
 int samples_count;

 AVFrame *frame;
 AVFrame *tmp_frame;

 AVPacket *tmp_pkt;

 float t, tincr, tincr2;

 struct SwsContext *sws_ctx;
 struct SwrContext *swr_ctx;
} OutputStream;

static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
{
 AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;

// printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
// av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
// av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
// av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
// pkt->stream_index);
}

static int write_frame(AVFormatContext *fmt_ctx, AVCodecContext *c,
 AVStream *st, AVFrame *frame, AVPacket *pkt)
{
 int ret;

 // send the frame to the encoder
 ret = avcodec_send_frame(c, frame);
 if (ret < 0) {
 fprintf(stderr, "Error sending a frame to the encoder");
 exit(1);
 }

 while (ret >= 0) {
 ret = avcodec_receive_packet(c, pkt);
 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
 break;
 else if (ret < 0) {
 fprintf(stderr, "Error encoding a frame\n");
 exit(1);
 }

 /* rescale output packet timestamp values from codec to stream timebase */
 av_packet_rescale_ts(pkt, c->time_base, st->time_base);
 pkt->stream_index = st->index;

 /* Write the compressed frame to the media file. */
 log_packet(fmt_ctx, pkt);
 ret = av_interleaved_write_frame(fmt_ctx, pkt);
 /* pkt is now blank (av_interleaved_write_frame() takes ownership of
 * its contents and resets pkt), so that no unreferencing is necessary.
 * This would be different if one used av_write_frame(). */
 if (ret < 0) {
 fprintf(stderr, "Error while writing output packet\n");
 exit(1);
 }
 }

 return ret == AVERROR_EOF ? 1 : 0;
}

/* Add an output stream. */
static void add_stream(OutputStream *ost, AVFormatContext *oc,
 const AVCodec **codec,
 enum AVCodecID codec_id)
{
 AVCodecContext *c;
 int i;

 /* find the encoder */
 *codec = avcodec_find_encoder(codec_id);
 if (!(*codec)) {
 fprintf(stderr, "Could not find encoder for '%s'\n",
 avcodec_get_name(codec_id));
 exit(1);
 }

 ost->tmp_pkt = av_packet_alloc();
 if (!ost->tmp_pkt) {
 fprintf(stderr, "Could not allocate AVPacket\n");
 exit(1);
 }

 ost->st = avformat_new_stream(oc, NULL);
 if (!ost->st) {
 fprintf(stderr, "Could not allocate stream\n");
 exit(1);
 }
 ost->st->id = oc->nb_streams-1;
 c = avcodec_alloc_context3(*codec);
 if (!c) {
 fprintf(stderr, "Could not alloc an encoding context\n");
 exit(1);
 }
 ost->enc = c;

 switch ((*codec)->type) {
 case AVMEDIA_TYPE_VIDEO:
 c->codec_id = codec_id;

 c->bit_rate = 400000;
 /* Resolution must be a multiple of two. */
 c->width = 352;
 c->height = 288;
 /* timebase: This is the fundamental unit of time (in seconds) in terms
 * of which frame timestamps are represented. For fixed-fps content,
 * timebase should be 1/framerate and timestamp increments should be
 * identical to 1. */
 ost->st->time_base = (AVRational){ 1, STREAM_FRAME_RATE };
 c->time_base = ost->st->time_base;

 c->gop_size = 12; /* emit one intra frame every twelve frames at most */
 c->pix_fmt = STREAM_PIX_FMT;
 if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
 /* just for testing, we also add B-frames */
 c->max_b_frames = 2;
 }
 if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
 /* Needed to avoid using macroblocks in which some coeffs overflow.
 * This does not happen with normal video, it just happens here as
 * the motion of the chroma plane does not match the luma plane. */
 c->mb_decision = 2;
 }
 break;

 default:
 break;
 }

 /* Some formats want stream headers to be separate. */
 if (oc->oformat->flags & AVFMT_GLOBALHEADER)
 c->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
}

/**************************************************************/
/* video output */

static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
{
 AVFrame *picture;
 int ret;

 picture = av_frame_alloc();
 if (!picture)
 return NULL;

 picture->format = pix_fmt;
 picture->width = width;
 picture->height = height;

 /* allocate the buffers for the frame data */
 ret = av_frame_get_buffer(picture, 0);
 if (ret < 0) {
 fprintf(stderr, "Could not allocate frame data.\n");
 exit(1);
 }

 return picture;
}

static void open_video(AVFormatContext *oc, const AVCodec *codec,
 OutputStream *ost, AVDictionary *opt_arg)
{
 int ret;
 AVCodecContext *c = ost->enc;
 AVDictionary *opt = NULL;

 av_dict_copy(&opt, opt_arg, 0);

 /* open the codec */
 ret = avcodec_open2(c, codec, &opt);
 av_dict_free(&opt);
 if (ret < 0) {
 fprintf(stderr, "Could not open video codec\n");
 exit(1);
 }

 /* allocate and init a re-usable frame */
 ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
 if (!ost->frame) {
 fprintf(stderr, "Could not allocate video frame\n");
 exit(1);
 }

 /* If the output format is not YUV420P, then a temporary YUV420P
 * picture is needed too. It is then converted to the required
 * output format. */
 ost->tmp_frame = NULL;
 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
 ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
 if (!ost->tmp_frame) {
 fprintf(stderr, "Could not allocate temporary picture\n");
 exit(1);
 }
 }

 /* copy the stream parameters to the muxer */
 ret = avcodec_parameters_from_context(ost->st->codecpar, c);
 if (ret < 0) {
 fprintf(stderr, "Could not copy the stream parameters\n");
 exit(1);
 }
}

/* Prepare a dummy image. */
static void fill_yuv_image(AVFrame *pict, int frame_index,
 int width, int height)
{
 int x, y, i;

 i = frame_index;

 /* Y */
 for (y = 0; y < height; y++)
 for (x = 0; x < width; x++)
 pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;

 /* Cb and Cr */
 for (y = 0; y < height / 2; y++) {
 for (x = 0; x < width / 2; x++) {
 pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
 pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
 }
 }
}

static AVFrame *get_video_frame(OutputStream *ost)
{
 AVCodecContext *c = ost->enc;

 /* check if we want to generate more frames */
 if (av_compare_ts(ost->next_pts, c->time_base,
 STREAM_DURATION, (AVRational){ 1, 1 }) > 0)
 return NULL;

 /* when we pass a frame to the encoder, it may keep a reference to it
 * internally; make sure we do not overwrite it here */
 if (av_frame_make_writable(ost->frame) < 0)
 exit(1);

 if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
 /* as we only generate a YUV420P picture, we must convert it
 * to the codec pixel format if needed */
 if (!ost->sws_ctx) {
 ost->sws_ctx = sws_getContext(c->width, c->height,
 AV_PIX_FMT_YUV420P,
 c->width, c->height,
 c->pix_fmt,
 SCALE_FLAGS, NULL, NULL, NULL);
 if (!ost->sws_ctx) {
 fprintf(stderr,
 "Could not initialize the conversion context\n");
 exit(1);
 }
 }
 fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
 sws_scale(ost->sws_ctx, (const uint8_t * const *) ost->tmp_frame->data,
 ost->tmp_frame->linesize, 0, c->height, ost->frame->data,
 ost->frame->linesize);
 } else {
 fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
 }

 ost->frame->pts = ost->next_pts++;

 return ost->frame;
}

/*
 * encode one video frame and send it to the muxer
 * return 1 when encoding is finished, 0 otherwise
 */
static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
{
 return write_frame(oc, ost->enc, ost->st, get_video_frame(ost), ost->tmp_pkt);
}

static void close_stream(AVFormatContext *oc, OutputStream *ost)
{
 avcodec_free_context(&ost->enc);
 av_frame_free(&ost->frame);
 av_frame_free(&ost->tmp_frame);
 av_packet_free(&ost->tmp_pkt);
 sws_freeContext(ost->sws_ctx);
 swr_free(&ost->swr_ctx);
}

/**************************************************************/
/* media file output */

int main(int argc, char **argv)
{
 OutputStream video_st = { 0 }, audio_st = { 0 };
 const AVOutputFormat *fmt;
 const char *filename;
 AVFormatContext *oc;
 const AVCodec *audio_codec, *video_codec;
 int ret;
 int have_video = 0, have_audio = 0;
 int encode_video = 0, encode_audio = 0;
 AVDictionary *opt = NULL;
 int i;

 if (argc < 2) {
 printf("usage: %s output_file\n"
 "API example program to output a media file with libavformat.\n"
 "This program generates a synthetic audio and video stream, encodes and\n"
 "muxes them into a file named output_file.\n"
 "The output format is automatically guessed according to the file extension.\n"
 "Raw images can also be output by using '%%d' in the filename.\n"
 "\n", argv[0]);
 return 1;
 }

 filename = argv[1];

 av_dict_set(&opt, "movflags", "frag_keyframe+separate_moof+omit_tfhd_offset+empty_moov", 0);

 /* allocate the output media context */
 avformat_alloc_output_context2(&oc, NULL, NULL, filename);
 if (!oc) {
 printf("Could not deduce output format from file extension: using MPEG.\n");
 avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
 }
 if (!oc)
 return 1;

 fmt = oc->oformat;

 /* Add the audio and video streams using the default format codecs
 * and initialize the codecs. */
 if (fmt->video_codec != AV_CODEC_ID_NONE) {
 add_stream(&video_st, oc, &video_codec, fmt->video_codec);
 have_video = 1;
 encode_video = 1;
 }

 /* Now that all the parameters are set, we can open the audio and
 * video codecs and allocate the necessary encode buffers. */
 if (have_video)
 open_video(oc, video_codec, &video_st, opt);


 av_dump_format(oc, 0, filename, 1);

 /* open the output file, if needed */
 if (!(fmt->flags & AVFMT_NOFILE)) {
 ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
 if (ret < 0) {
 fprintf(stderr, "Could not open '%s'\n", filename);
 return 1;
 }
 }

 /* Write the stream header, if any. */
 ret = avformat_write_header(oc, &opt);
 if (ret < 0) {
 fprintf(stderr, "Error occurred when opening output file\n");
 return 1;
 }

 while (encode_video || encode_audio) {
 /* select the stream to encode */
 if (encode_video &&
 (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
 audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
 encode_video = !write_video_frame(oc, &video_st);
 }
 }

 av_write_trailer(oc);

 /* Close each codec. */
 if (have_video)
 close_stream(oc, &video_st);
 if (have_audio)
 close_stream(oc, &audio_st);

 if (!(fmt->flags & AVFMT_NOFILE))
 /* Close the output file. */
 avio_closep(&oc->pb);

 /* free the stream */
 avformat_free_context(oc);

 return 0;
}
</cmath></cstring></cstdio></cstdlib>

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