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• Giving Thanks For VP8

  25 novembre 2010, par Multimedia Mike — VP8

  It’s the Thanksgiving holiday here in the United States. I guess that’s as good a reason as any to release a first cut of my VP8 encoder. In order to remind people that they shouldn’t expect phenomenal quality from it — and to discourage inexperienced people from trying to create useful videos with it — I have hardcoded the quantizers to their maximum settings. For those not skilled in the art, this is the setting that yields maximum compression and worst quality. When compressing the Big Buck Bunny logo image, the resulting file is only 2839 bytes but observe the reconstructed quality :

  
  
  It really just looks like a particularly stormy day in the forest.
  

  First VP8 File From An Independent Encoder
  I found a happy medium on the quantizer scale and encoded the first 30 seconds of Big Buck Bunny for your inspection. I guess this makes it the first VP8/WebM file from an independent encoder (using FFmpeg’s Matroska muxer as well).

  Download : bbb-360p-30sec-q40.webm ( 13 MBytes)

  I think the quality makes it look like it was digitized from an old VHS tape.

  For fun, here’s the version with the quantizer cranked to the max : bbb-360p-30sec-q127.webm ( 1.3 MBytes)

  Aside : I was going to encapsulate the video in this post using a bare HTML5 <video> tag for the benefit of the small browsing population who could view that (indeed, it works fine in Chrome). But that would be insane due to the fact that supporting browsers preload the video with no easy (read : without the help of JavaScript) method for overriding this unacceptable default.

  The Code
  I’m still trying to get over my fear of git. To that end, I have posted the code on Github :

  https://github.com/multimediamike/ffvp8enc

  I still don’t like you, git. But I’m sure we’ll find some way to make this work.

  Other required code changes in the basic FFmpeg tree :

  • Of course, copy vp8enc.c into libavcodec/
  • In libavcodec/allcodecs.c, ’REGISTER_DECODER (VP8, vp8);’ turns into ’REGISTER_ENCDEC (VP8, vp8);’
  • Add ’OBJS-$(CONFIG_VP8_ENCODER) += vp8enc.o’ to libavcodec/Makefile

  Further Work
  About the limitations and work yet to do :

  • it’s still intra-only, no interframes (which is where a lot of compression occurs)
  • no rate control or distortion optimization, obviously
  • no intra 4x4 coding (that’s close to working but didn’t my little T-day deadline)
  • no quantization control ; this should really be hooked up to the FFmpeg command line but I’m not sure how
  • encoder writes into a static-sized, 1/2 MB memory buffer ; this can overflow
  • code is a mess (what did you expect at this stage of the game ?)
  • lots and lots of other things, surely

• How can I render a video in real time with custom parameters ?

  18 décembre 2024, par Joaquín L. Robles

  Is it possible to render a video in real time with custom parameters ? I'm trying to inject some parameters (text, image and other video portions) into a video template depending on user parameters, like the "Facebook 10 Years video"..

  &#xA;&#xA;

  The output format should be any video format such as H.264.

  &#xA;&#xA;

  I've been googling and asking and the closest I got is to make a video from HTML5 canvas captures, which I think is totally inefficient.

  &#xA;&#xA;

  Any insight or guidance would be great, thanks

  &#xA;

• FFmpeg fails to draw text

  6 avril 2024, par Edoardo Balducci

  I've rarely used ffmpeg before, so, sorry If the question is too dumb.&#xA;I have a problem adding a text layer to a video frame using ffmpeg.

  &#xA;

  This is my current code :

  &#xA;

  import subprocess
from PyQt5.QtGui import QPixmap, QImage
from PyQt5.QtWidgets import QLabel

class VideoThumbnailLabel(QLabel):
    def __init__(self, file_path, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.video = video
        video_duration = self.get_video_duration(file_path)
        thumbnail_path = self.get_thumbnail(file_path, video_duration)
        if thumbnail_path:
            self.setPixmap(QPixmap(thumbnail_path).scaled(160, 90, Qt.KeepAspectRatio))
        self.setToolTip(f"{video.title}\n{video.description}")

    def get_video_duration(self, video_path):
        """Returns the duration of the video in seconds."""
        command = [
            'ffprobe', '-v', 'error', '-show_entries',
            'format=duration', '-of',
            'default=noprint_wrappers=1:nokey=1', video_path
        ]
        try:
            result = subprocess.run(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
            if result.returncode != 0:
                print(f"ffprobe error: {result.stderr}")
                return 0
            duration = float(result.stdout)
            return int(duration)  # Returning duration as an integer for simplicity
        except Exception as e:
            print(f"Error getting video duration: {e}")
            return 0

    def get_thumbnail(self, video_path, duration):
        """Generates a thumbnail with the video duration overlaid."""
        output_path = "thumbnail.jpg"  # Temporary thumbnail file
        duration_str = f"{duration // 3600:02d}:{(duration % 3600) // 60:02d}:{duration % 60:02d}"
        command = [
            'ffmpeg', '-i', video_path,
            '-ss', '00:00:01',  # Time to take the screenshot
            '-frames:v', '1',  # Number of frames to capture
            '-vf', f"drawtext=text='Duration: {duration_str}':x=10:y=10:fontsize=24:fontcolor=white",
            '-q:v', '2',  # Output quality
            '-y',  # Overwrite output files without asking
            output_path
        ]
        try:
            result = subprocess.run(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            if result.returncode != 0:
                print(f"ffmpeg error: {result.stderr}")
                return None
            return output_path
        except Exception as e:
            print(f"Error generating thumbnail with duration: {e}")
            return None


  &#xA;

  and it is used like this :

  &#xA;

  for i, video in enumerate(self.videos):
    video_widget = VideoThumbnailLabel(video.file)
    video_widget.mousePressEvent = lambda event, v=video: self.onThumbnailClick(
        v
    )
    self.layout.addWidget(video_widget, i // 3, i % 3)


  &#xA;

  I'm facing a problem where I am not able to get the thumbnail if I try to add the duration (I've tested it without the draw filter and worked fine)

  &#xA;

  I get this error (from the result.returncode) that I'm not able to comprehend :

  &#xA;

  ffmpeg error: b"ffmpeg version 6.1.1 Copyright (c) 2000-2023 the FFmpeg developers\n  built with Apple clang version 15.0.0 (clang-1500.1.0.2.5)\n  configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/6.1.1_4 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopenvino --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon\n  libavutil      58. 29.100 / 58. 29.100\n  libavcodec     60. 31.102 / 60. 31.102\n  libavformat    60. 16.100 / 60. 16.100\n  libavdevice    60.  3.100 / 60.  3.100\n  libavfilter     9. 12.100 /  9. 12.100\n  libswscale      7.  5.100 /  7.  5.100\n  libswresample   4. 12.100 /  4. 12.100\n  libpostproc    57.  3.100 / 57.  3.100\nInput #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/edoardo/Projects/work/test/BigBuckBunny.mp4':\n  Metadata:\n    major_brand     : mp42\n    minor_version   : 0\n    compatible_brands: isomavc1mp42\n    creation_time   : 2010-01-10T08:29:06.000000Z\n  Duration: 00:09:56.47, start: 0.000000, bitrate: 2119 kb/s\n  Stream #0:0[0x1](und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 125 kb/s (default)\n    Metadata:\n      creation_time   : 2010-01-10T08:29:06.000000Z\n      handler_name    : (C) 2007 Google Inc. v08.13.2007.\n      vendor_id       : [0][0][0][0]\n  Stream #0:1[0x2](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1280x720 [SAR 1:1 DAR 16:9], 1991 kb/s, 24 fps, 24 tbr, 24k tbn (default)\n    Metadata:\n      creation_time   : 2010-01-10T08:29:06.000000Z\n      handler_name    : (C) 2007 Google Inc. v08.13.2007.\n      vendor_id       : [0][0][0][0]\n[Parsed_drawtext_0 @ 0x60000331cd10] Both text and text file provided. Please provide only one\n[AVFilterGraph @ 0x600002018000] Error initializing filters\n[vost#0:0/mjpeg @ 0x13ce0c7e0] Error initializing a simple filtergraph\nError opening output file thumbnail.jpg.\nError opening output files: Invalid argument\n"


  &#xA;

  I've installed both ffmpeg and ffmprobe in my machine :

  &#xA;

  ┌(edoardomacbook-air)-[~/Projects/work/tests-scripts]                                                                                                                                   
└─ $ ffmpeg -version && ffprobe -version                                                                                                                                                              2 ⚙ 
ffmpeg version 6.1.1 Copyright (c) 2000-2023 the FFmpeg developers
built with Apple clang version 15.0.0 (clang-1500.1.0.2.5)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/6.1.1_4 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopenvino --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
libavutil      58. 29.100 / 58. 29.100
libavcodec     60. 31.102 / 60. 31.102
libavformat    60. 16.100 / 60. 16.100
libavdevice    60.  3.100 / 60.  3.100
libavfilter     9. 12.100 /  9. 12.100
libswscale      7.  5.100 /  7.  5.100
libswresample   4. 12.100 /  4. 12.100
libpostproc    57.  3.100 / 57.  3.100
ffprobe version 6.1.1 Copyright (c) 2007-2023 the FFmpeg developers
built with Apple clang version 15.0.0 (clang-1500.1.0.2.5)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/6.1.1_4 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopenvino --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
libavutil      58. 29.100 / 58. 29.100
libavcodec     60. 31.102 / 60. 31.102
libavformat    60. 16.100 / 60. 16.100
libavdevice    60.  3.100 / 60.  3.100
libavfilter     9. 12.100 /  9. 12.100
libswscale      7.  5.100 /  7.  5.100
libswresample   4. 12.100 /  4. 12.100
libpostproc    57.  3.100 / 57.  3.100


  &#xA;

  Does anyone see the problem ?

  &#xA;

  ---

  &#xA;

  P.S. : I know that I havent provided a minimal reproducible example, but since I don't know where the problem lies I didn't want to exclude anything

  &#xA;