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Revolution of Open-source and film making towards open film making
6 octobre 2011, par
Mis à jour : Juillet 2013
Langue : English
Type : Texte
Sur d’autres sites (1907)
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How to Save and Display a Video Simultaneously using C# Aforge.NET framework ?
8 avril 2014, par AkshayI am able to display the video from my webcam or any other integrated device into a picturebox . Also i am able to Save the video into an avi file using FFMPEG DLL files.
I want to do both things simultaneously ie Save the video in the avi file as well as at the same time display the live feed too.
This is for a surveillance project where i want to monitor the live feed and save those too.using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using AForge.Video;
using AForge.Video.DirectShow;
using AForge.Video.FFMPEG;
using AForge.Video.VFW;
using System.Drawing.Imaging;
using System.IO;
namespace cam_aforge1
{
public partial class Form1 : Form
{
private bool DeviceExist = false;
private FilterInfoCollection videoDevices;
private VideoCaptureDevice videoSource = null;
public Form1()
{
InitializeComponent();
}
private void getCamList()
{
try
{
videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
comboBox1.Items.Clear();
if (videoDevices.Count == 0)
throw new ApplicationException();
DeviceExist = true;
foreach (FilterInfo device in videoDevices)
{
comboBox1.Items.Add(device.Name);
}
comboBox1.SelectedIndex = 0; //make dafault to first cam
}
catch (ApplicationException)
{
DeviceExist = false;
comboBox1.Items.Add("No capture device on your system");
}
}
private void rfsh_Click(object sender, EventArgs e)
{
getCamList();
}
private void start_Click(object sender, EventArgs e)
{
if (start.Text == "&Start")
{
if (DeviceExist)
{
videoSource = new VideoCaptureDevice(videoDevices[comboBox1.SelectedIndex].MonikerString);
videoSource.NewFrame += new NewFrameEventHandler(video_NewFrame);
videoSource.NewFrame += new NewFrameEventHandler(video_NewFrameSave);
CloseVideoSource();
videoSource.DesiredFrameSize = new Size(160, 120);
//videoSource.DesiredFrameRate = 10;
videoSource.Start();
label2.Text = "Device running...";
start.Text = "&Stop";
timer1.Enabled = true;
}
else
{
label2.Text = "Error: No Device selected.";
}
}
else
{
if (videoSource.IsRunning)
{
timer1.Enabled = false;
CloseVideoSource();
label2.Text = "Device stopped.";
start.Text = "&Start";
}
}
}
private void video_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
Bitmap img = (Bitmap)eventArgs.Frame.Clone();
pictureBox1.Image = img;
}
Bitmap imgsave;
private void video_NewFrameSave(object sender, NewFrameEventArgs eventArgs)
{
imgsave = (Bitmap)eventArgs.Frame.Clone();
}
private void CloseVideoSource()
{
if (!(videoSource == null))
if (videoSource.IsRunning)
{
videoSource.SignalToStop();
videoSource = null;
}
}
private void timer1_Tick(object sender, EventArgs e)
{
label2.Text = "Device running... " + videoSource.FramesReceived.ToString() + " FPS";
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
CloseVideoSource();
}
private void Form1_Load(object sender, EventArgs e)
{
}
VideoFileWriter writer;
private void button1_Click(object sender, EventArgs e)
{
int width = 640;
int height = 480;
writer = new VideoFileWriter();
writer.Open("test.avi", width, height, 75, VideoCodec.MPEG4);
for (int i = 0; i < 5000; i++)
{
writer.WriteVideoFrame(imgsave);
}
}
private void button2_Click(object sender, EventArgs e)
{
writer.Close();
}
}
}Thanks in advance.
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ffmpeg not converting via PHP script
16 mars 2014, par user3331834Essentially, I have this code :
if(in_array($ext,$audio)&&($ext!=="flac")){
exec("ffmpeg -i -loglevel 'verbose' ".$fileName.".".$ext." ".$fileName.".flac null >/dev/null 2>/var/www/resources/ffmpegAudio.log &",$ffmpegOutput);
print_r($ffmpegOutput);
$editApproveStatus="Audio entry approved. File converted.";
}Ultimately, my goal is to convert files and show a live progress of the conversion (or at least something that updates every few seconds), and running in the background, so that the same page can be used to convert further files.
Now I'm already stuck, because the conversion just isn't working. I know that the preceding code should be fine, since it makes it all the way to this if statement above, and no errors are being throw up by the PHP. However, my log output shows :
ffmpeg version 0.8.10-6:0.8.10-0ubuntu0.13.10.1, Copyright (c) 2000-2013 the Libav developers
built on Feb 6 2014 20:59:46 with gcc 4.8.1
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
-loglevel: No such file or directoryWhich also leads me to another question : If ffmpeg is deprecated, and avconv is the way to do, can I still use the exec code in my PHP as is (replacing the ffmpeg bit with avconv) ? From what I've seen so far on the avconv page, it looks similar, but I can't be certain that it's exactly the same.
So my two questions : Why isn't the file being converted, and is there any change in the syntax between avconv and ffmpeg ?
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Problems of using MediaCodec.getOutputFormat() for an encoder in Android 4.1/4.2 devices
13 mars 2014, par MarkI'm trying to use MediaCodec to encode frames (either by camera or decoder) into a video.
When processing the encoder output by dequeueOutputBuffer(), I expect to receive the return index = MediaCodec.INFO_OUTPUT_FORMAT_CHANGED, so I can call getOutputFormat() to get the encoder output format as the input of the currently used ffmpeg muxer.I have tested some pad/phone devices with Android version 4.1 4.3. All of them have at least one hardware video AVC encoder and is used in the test. On the devices with version 4.3, the encoder gives MediaCodec.INFO_OUTPUT_FORMAT_CHANGED before writing the encoded data as expected, and the output format returned from getOutputFormat() can be used by the muxer correctly. On the devices with 4.2.2 or lower, the encoder never gives MediaCodec.INFO_OUTPUT_FORMAT_CHANGED while it can still output the encoded elementary stream, but the muxer cannot know the exact output format.
I want to ask the following questions :
- Does the behavior of encoder (gives MediaCodec.INFO_OUTPUT_FORMAT_CHANGED or not before outputing encoded data) depend on the Android API Level or the chips on individual devices ?
- If the encoder writes data before MediaCodec.INFO_OUTPUT_FORMAT_CHANGED appears, is there any way to get the output format of the encoded data ?
- The encoder still output the codec config data (with flag MediaCodec.BUFFER_FLAG_CODEC_CONFIG) on the devices before the encoded data. It is mostly used to config a decoder, but can I derive the output format by the codec config data ?
I have tried these solutions to get the output format but failed :
- Call getOutputFormat() frequently during the whole encode process. However, all of them throw IllegalStateException without the appearance of MediaCodec.INFO_OUTPUT_FORMAT_CHANGED.
-
Use the initial MediaFormat use to config the encoder at the beginning, like the example :
m_init_encode_format = MediaFormat.createVideoFormat(m_encode_video_mime, m_frame_width, m_frame_height);
int encode_bit_rate = 3000000;
int encode_frame_rate = 15;
int encode_iframe_interval = 2;
m_init_encode_format.setInteger(MediaFormat.KEY_COLOR_FORMAT, m_encode_color_format);
m_init_encode_format.setInteger(MediaFormat.KEY_BIT_RATE, encode_bit_rate);
m_init_encode_format.setInteger(MediaFormat.KEY_FRAME_RATE, encode_frame_rate);
m_init_encode_format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, encode_iframe_interval);
m_encoder = MediaCodec.createByCodecName(m_video_encoder_codec_info.getName());
m_encoder.configure(m_init_encode_format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
// Assume m_init_encode_format is the output format of the encoderHowever it fails since the output format of the encoder is still "changed" from the initial one.
Please help me to realize the behavior of an encoder, and if there is any solution to query the output format if the required MediaCodec.INFO_OUTPUT_FORMAT_CHANGED is missing.
By comparing the output format and the codec config data, the missing fields are csd-0, csd-1, and a "what" field with value = 1869968451.
(I do not understand the "what" field. It seems to be a constant and is not required. Can anyone tell me about its meaning ?)If I parse the codec config data as the csd-1 field (last 8 bytes) and csd-0 field (remaining bytes), it seems that the muxer can work correctly and output a video playable on all of the testing devices.
(But I want to ask : is this 8-byte assumption correct, or there is more reliable way to parse the data ?)However, I got another problem that If I decode the video by Android MediaCodec again, the BufferInfo.presentationTimeUs value get by dequeueOutputBuffer() is 0 for most of the decoded frames. Only the last few frames has correct time. The sample time get by MediaExtractor.getSampleTime() is correct and exactly the value I set to the encoder/muxer, but the decoded frame time is not. This issue only happen on 4.2.2 or lower device.
It is strange that the frame time is incorrect but the video can be playback in correct speed on the device. (Most of the devices with 4.2.2 or lower I've tested has only 1 Video AVC decoder.) Do I need to set other fields that may affect the presentation time ?
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