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• animated webp only has key frame？

  23 février 2024, par Feilong Luo

  I want to cover a mp4 to animated webp, so I use the following ffmpeg command :

  


  My mp4 file is from http://myvideodata.oss-cn-shenzhen.aliyuncs.com/crs_bcb3f246273d4dbb8ec7f93239fbea6e.mp4

  


  ffmpeg -i ./test.mp4 test.webp


  


  It is ok, and animated webp has been created, so I use webpinfo tool (downloaded from https://developers.google.com/speed/webp/download and build example in it, or use this one http://myvideodata.oss-cn-shenzhen.aliyuncs.com/webpinfo)

  


  webpinfo test.webp


  


  and get information like this :

  


  RIFF HEADER:
  File size: 1968244
Chunk VP8X at offset     12, length     18
  ICCP: 0
  Alpha: 1
  EXIF: 0
  XMP: 0
  Animation: 1
  Canvas size 362 x 330
Chunk ANIM at offset     30, length     14
  Background color:(ARGB) ff ff ff ff
  Loop count      : 1
Chunk ANMF at offset     44, length  25116
  Offset_X: 0
  Offset_Y: 0
  Width: 362
  Height: 330
  Duration: 42
  Dispose: 0
  Blend: 0
Chunk VP8  at offset     68, length  25092
  Width: 362
  Height: 330
  Alpha: 0
  Animation: 0
  Format: Lossy (1)


  


  Every frame size is about 25k, my question is : all frames in animated webp are key frames ?

  


  Can anyone help ?

  


• Workflow and data format for sending MediaRecorder output to express server

  30 avril 2021, par Max

  I've been trying to figure this out for a while but got lost between different ways of sending files and different data formats.

  


  I am recording the stream of a canvas animation with MediaRecorder. As far as I understand this returns a blob with the video in binary format. Now I want to send this data to my express server and convert it to an h264 encoded mp4 file. My first impulse was to use ffmpeg on the server. Unfortunately I'm struggling with the details of the implementation. I am unsure on how to best transmit the data and in what format and how to feed it to ffmpeg.

  


  This is what I have on the client side :

  


  // Get stream from element
stream = element.captureStream(30)

// Create media recorder with stream
const recorder = new MediaRecorder(stream)

// Save to file
recorder.ondataavailable = ({ data }) => {
                
    const formData = new FormData()
    formData.append("file", data)

    const options = {
        method: "POST",
        body: formData,
    }

    fetch("http://localhost:3001/api/blob_to_mp4", options).then(
        (res) => {
            console.log(res)
        }
    )
}


  


  And this is what I have on the server side :

  


  "use strict";

const express = require("express");
const cors = require("cors");
const ffmpeg = require("fluent-ffmpeg");
const fs = require("fs");

const port = process.env.PORT || 3001;
const app = express();
var command = ffmpeg();

app.use(cors());
app.use(express.urlencoded({ extended: true }));
app.use(express.json());

app.post("/api/blob_to_mp4", function (req, res) {
  var data = Buffer.from("");

  // Add data
  req.on("data", function (chunk) {
    data = Buffer.concat([data, chunk]);
  });

  // Full data available
  req.on("end", () => {
    req.rawBody = data;
  });

  res.send("hello world");
});

app.listen(port);
console.log(`Server running on port ${port}`);


  


• Cannot convert webm video and audio to mp4 [closed]

  19 décembre 2019, par HHH837

  I am trying to record video and audio in canvas using RecordRTC and converting it to mp4 but getting below error. Please suggest me the command for ffmpeg to fix the issue.

  Received command: -i video.webm -i audio.webm -c:v mpeg4 -c:a aac -b:v 6400k -b:a 4800k -strict experimental output.mp4.  Processing with 268435456 bits.
  
  configuration: --cc=emcc --enable-cross-compile --target-os=none --arch=x86_32 --cpu=generic --disable-ffplay --disable-ffprobe --disable-ffserver --disable-a`enter code here`sm --disable-doc --disable-devices --disable-pthreads --disable-w32threads --disable-network --disable-hwaccels --disable-parsers --disable-bsfs --disable-debug --disable-zlib --disable-protocols --disable-indevs --disable-outdevs --enable-protocol=file --enable-pic --enable-small
  
  libavutil      52. 52.100 / 52. 52.100
  
  libavcodec     55. 41.100 / 55. 41.100
  
  libavformat    55. 21.100 / 55. 21.100
  
  libavdevice    55.  5.100 / 55.  5.100
  
  libavfilter     3. 90.102 /  3. 90.102
  
  libswscale      2.  5.101 /  2.  5.101
  
  libswresample   0. 17.104 /  0. 17.104
  
  [vp8 @ 0xcba330] Warning: not compiled with thread support, using thread emulation
  
  Input #0, matroska,webm, from 'video.webm':
  
  Duration: N/A, start: 0.000000, bitrate: N/A
  
  Stream #0:0(eng): Video: vp8, yuv420p, 300x400, SAR 1:1 DAR 3:4, 1k tbr, 1k tbn, 1k tbc (default)
  
  Metadata:
  
  alpha_mode      : 1
  
  Guessed Channel Layout for  Input Stream #1.0 : stereo
  
  Input #1, matroska,webm, from 'audio.webm':
  
  Duration: N/A, start: 0.000000, bitrate: N/A
  
  Stream #1:0(eng): Audio: opus, 48000 Hz, stereo (default)
  
  [graph 1 input from stream 1:0 @ 0xccf4c0] Invalid sample format (null)
  
  Error opening filters!
  
  Finished processing (took 3688ms)
  
  {"type":"done","data":[{"name":"output.mp4","data":{}}],"time":3688}
  
  {"name":"output.mp4","data":{}}