Extracting audio from video command fails for some videos - audio

I am using below FFmpeg command for extracting audio from video-
String[] complexCommand = new String[]{"-y","-ss", "" +
startMs / 1000, "-t", "" + (endMs - startMs) / 1000, "-i",
inputFileAbsolutePath, "-vn", "-ar", "44100", "-ac", "2", "-b:a",
"256k", "-f", "mp3", outputFileAbsolutePath};
It works fine in my device but through analytics I came to know that its failing for many users or for many videos.I failed to understand whats wrong with the command and why its failing many times?

Related

Is there a way to check the volume level of all processes with pipewire/pulseaudio?

I'm trying to find a way to check if i have any desktop audio AND what processes is producing sounds.
After some searching i found a way to list all the sink input in pipewire/pulseaudio using pactl list sink-inputs however i have no idea if that input is muted or not
example output:
Sink Input #512
Driver: protocol-native.c
Owner Module: 9
Client: 795
Sink: 1
Sample Specification: float32le 2ch 48000Hz
Channel Map: front-left,front-right
Format: pcm, format.sample_format = "\"float32le\"" format.rate = "48000" format.channels = "2" format.channel_map = "\"front-left,front-right\""
Corked: yes
Mute: no
Volume: front-left: 43565 / 66% / -10.64 dB, front-right: 43565 / 66% / -10.64 dB
balance 0.00
Buffer Latency: 165979 usec
Sink Latency: 75770 usec
Resample method: speex-float-1
Properties:
media.name = "Polish cow (English Lyrics Full Version) - YouTube"
application.name = "Firefox"
native-protocol.peer = "UNIX socket client"
native-protocol.version = "35"
application.process.id = "612271"
application.process.user = "user"
application.process.host = "host"
application.process.binary = "firefox"
application.language = "en_US.UTF-8"
window.x11.display = ":0"
application.process.machine_id = "93e71eeba04e43789f0972b7ea0e4b39"
application.process.session_id = "2"
application.icon_name = "firefox"
module-stream-restore.id = "sink-input-by-application-name:Firefox"
The obvious thing would be looking at the Mute and Volume line but that is not reliable at all, currently the youtube video is paused but Mute is show as no and Volume is still no different from when the youtube video is actually playing.
I need the solution to be script-able since I'll muting certain thing when there is another process that is making sounds, and play it again when there is no sound, using bash script. If it is not possible on pipewire/pulseaudio but it is possible with another sound server then please do tell me.

while merging audio and video with fmpeg, audio is playing but video is not working in android studio

I have try multiples commands but same issue occours, many commands work fines but in output audio work fines but vedio is not showing I am using this library
implementation 'com.arthenica:mobile-ffmpeg-full:4.4'
here is my code
val ccommand = arrayOf(
"-i",
vedioname,
"-i",
audioname,
"-c:v",
"copy",
"-c:a",
"aac",
"-shortest",
fileName!!.path
)
val rc = FFmpeg.execute(cmd)

Reading console output from mplayer to parse track's position/length

When you run mplayer, it will display the playing track's position and length (among some other information) through, what I'd assume is, stdout.
Here's a sample output from mplayer:
MPlayer2 2.0-728-g2c378c7-4+b1 (C) 2000-2012 MPlayer Team
Cannot open file '/home/pi/.mplayer/input.conf': No such file or directory
Failed to open /home/pi/.mplayer/input.conf.
Cannot open file '/etc/mplayer/input.conf': No such file or directory
Failed to open /etc/mplayer/input.conf.
Playing Bomba Estéreo - La Boquilla [Dixone Remix].mp3.
Detected file format: MP2/3 (MPEG audio layer 2/3) (libavformat)
[mp3 # 0x75bc15b8]max_analyze_duration 5000000 reached
[mp3 # 0x75bc15b8]Estimating duration from bitrate, this may be inaccurate
[lavf] stream 0: audio (mp3), -aid 0
Clip info:
album_artist: Bomba Estéreo
genre: Latin
title: La Boquilla [Dixone Remix]
artist: Bomba Estéreo
TBPM: 109
TKEY: 11A
album: Unknown
date: 2011
Load subtitles in .
Selected audio codec: MPEG 1.0/2.0/2.5 layers I, II, III [mpg123]
AUDIO: 44100 Hz, 2 ch, s16le, 320.0 kbit/22.68% (ratio: 40000->176400)
AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample)
Video: no video
Starting playback...
A: 47.5 (47.4) of 229.3 (03:49.3) 4.1%
The last line (A: 47.5 (47.4) of 229.3 (03:49.3) 4.1%) is what I'm trying to read but, for some reason, it's never received by the Process.OutputDataReceived event handler.
Am I missing something? Is mplayer using some non-standard way of outputting the "A:" line to the console?
Here's the code in case it helps:
Public Overrides Sub Play()
player = New Process()
player.EnableRaisingEvents = True
With player.StartInfo
.FileName = "mplayer"
.Arguments = String.Format("-ss {1} -endpos {2} -volume {3} -nolirc -vc null -vo null ""{0}""",
tmpFileName,
mTrack.StartTime,
mTrack.EndTime,
100)
.CreateNoWindow = False
.UseShellExecute = False
.RedirectStandardOutput = True
.RedirectStandardError = True
.RedirectStandardInput = True
End With
AddHandler player.OutputDataReceived, AddressOf DataReceived
AddHandler player.ErrorDataReceived, AddressOf DataReceived
AddHandler player.Exited, Sub() KillPlayer()
player.Start()
player.BeginOutputReadLine()
player.BeginErrorReadLine()
waitForPlayer.WaitOne()
KillPlayer()
End Sub
Private Sub DataReceived(sender As Object, e As DataReceivedEventArgs)
If e.Data = Nothing Then Exit Sub
If e.Data.Contains("A: ") Then
' Parse the data
End If
End Sub
Apparently, the only solution is to run mplayer in "slave" mode, as explained here: http://www.mplayerhq.hu/DOCS/tech/slave.txt
In this mode we can send commands to mplayer (via stdin) and the response (if any) will be sent via stdout.
Here's a very simple implementation that displays mplayer's current position (in seconds):
using System;
using System.Threading;
using System.Diagnostics;
using System.Collections.Generic;
namespace TestMplayer {
class MainClass {
private static Process player;
public static void Main(string[] args) {
String fileName = "/home/pi/Documents/Projects/Raspberry/RPiPlayer/RPiPlayer/bin/Electronica/Skrillex - Make It Bun Dem (Damian Marley) [Butch Clancy Remix].mp3";
player = new Process();
player.EnableRaisingEvents = true;
player.StartInfo.FileName = "mplayer";
player.StartInfo.Arguments = String.Format("-slave -nolirc -vc null -vo null \"{0}\"", fileName);
player.StartInfo.CreateNoWindow = false;
player.StartInfo.UseShellExecute = false;
player.StartInfo.RedirectStandardOutput = true;
player.StartInfo.RedirectStandardError = true;
player.StartInfo.RedirectStandardInput = true;
player.OutputDataReceived += DataReceived;
player.Start();
player.BeginOutputReadLine();
player.BeginErrorReadLine();
Thread getPosThread = new Thread(GetPosLoop);
getPosThread.Start();
}
private static void DataReceived(object o, DataReceivedEventArgs e) {
Console.Clear();
Console.WriteLine(e.Data);
}
private static void GetPosLoop() {
do {
Thread.Sleep(250);
player.StandardInput.Write("get_time_pos" + Environment.NewLine);
} while(!player.HasExited);
}
}
}
I found the same problem with another application that works more or less in a similar way (dbPowerAmp), in my case, the problem was that the process output uses Unicode encoding to write the stdout buffer, so I have to set the StandardOutputEncoding and StandardError to Unicode to be able start reading.
Your problem seems to be the same, because if "A" cannot be found inside the output that you published which clearlly shows that existing "A", then probably means that the character differs when reading in the current encoding that you are using to read the output.
So, try setting the proper encoding when reading the process output, try setting them to Unicode.
ProcessStartInfo.StandardOutputEncoding
ProcessStartInfo.StandardErrorEncoding
Using "read" instead of "readline", and treating the input as binary, will probably fix your problem.
First off, yes, mplayer slave mode is probably what you want. However, if you're determined to parse the console output, it is possible.
Slave mode exists for a reason, and if you're half serious about using mplayer from within your program, it's worth a little time to figure out how to properly use it. That said, I'm sure there's situations where the wrapper is the appropriate approach. Maybe you want to pretend that mplayer is running normally, and control it from the console, but secretly monitor file position to resume it later? The wrapper might be easier than translating all of mplayers keyboard commands into slave mode commands?
Your problem is likely that you're trying to use "readline" from within python on an endless line. That line of output contains \r instead of \n as the line separator, so readline will treat it as a single endless line. sed also fails this way, but other commands (such as grep) treat \r as \n under some circumstances.
Handling of \r is inconsistent, and can't be relied on. For instance, my version of grep treats \r as \n when matching IF output is a console, and uses \n to seperate the output. But if output is a pipe, it treats it as any other character.
For instance:
mplayer TMBG-Older.mp3 2>/dev/null | tr '\r' '\n' | grep "^A: " | sed 's/^A: *\([0-9.]*\) .*/\1/' | tail -n 1
I'm using "tr" here to force it to '\n', so other commands in the pipe can deal with it in a consistent manner.
This pipeline of commands outputs a single line, containing ONLY the ending position in seconds, with decimal point. But if you remove the "tr" command from this pipe, bad things happen. On my system, it shows only "0.0" as the position, as "sed" doesn't deal well with the '\r' line separators, and ALL the position updates are treated as the same line.
I'm fairly sure python doesn't handle \r well either, and that's likely your problem. If so, using "read" instead of "readline" and treating it like binary is probably the correct solution.
There are other problems with this approach though. Buffering is a big one. ^C causes this command to output nothing, mplayer must quit gracefully to show anything at all, as pipelines buffers things, and buffers get discarded on SIGINT.
If you really wanted to get fancy, you could probably cat several input sources together, tee the output several ways, and REALLY write a wrapper around mplayer. A wrapper that's fragile, complicated, and might break every time mplayer is updated, a user does something unexpected, or the name of the file being played contains something weird, SIGSTOP or SIGINT. And probably other things that I haven't though of.

Linux ALSA Driver using channel count 3

Am running my ALSA Driver on Ubuntu 14.04, 64bit, 3.16.0-30-generic Kernel.
Hardware is proprietary hardware, hence cant give much details.
Following is the existing driver implementation:
Driver is provided sample format, sample rate, channel_count as input via module parameter. (Due to requirements need to provide inputs via module parameters)
Initial snd_pcm_hardware structure for playback path.
#define DEFAULT_PERIOD_SIZE (4096)
#define DEFAULT_NO_OF_PERIODS (1024)
static struct snd_pcm_hardware xxx_playback =
{
.info = SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_SYNC_START,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.rates = (SNDRV_PCM_RATE_8000 | \
SNDRV_PCM_RATE_16000 | \
SNDRV_PCM_RATE_48000 | \
SNDRV_PCM_RATE_96000),
.rate_min = 8000,
.rate_max = 96000,
.channels_min = 1,
.channels_max = 1,
.buffer_bytes_max = (DEFAULT_PERIOD_SIZE * DEFAULT_NO_OF_PERIODS),
.period_bytes_min = DEFAULT_PERIOD_SIZE,
.period_bytes_max = DEFAULT_PERIOD_SIZE,
.periods_min = DEFAULT_NO_OF_PERIODS,
.periods_max = DEFAULT_NO_OF_PERIODS,
};
Similar values for captures side snd_pcm_hardware structure.
Please, note that the following below values are replaced in playback open entry point, based on the current audio test configuration:
(user provides audio format, audio rate, ch count via module parameters as inputs to the driver, which are refilled in snd_pcm_hardware structure)
xxx_playback.formats = user_format_input
xxx_playback.rates = xxx_playback.rate_min, xxx_playback.rate_max = user_sample_rate_input
xxx_playback.channels_min = xxx_playback.channels_max = user_channel_input
Similarly values are re-filled for capture snd_pcm_hardware structure in capture open entry point.
Hardware is configured for clocks based on channel_count, format, sample_rate and driver registers successfully with ALSA layer
Found aplay/arecord working fine for channel_count = 1 or 2 or 4
During aplay/arecord, in driver when "runtime->channels" value is checked, it reflects the channel_count configured, which sounds correct to me.
Record data matches with played, since its a loop back test.
But when i use channel_count = 3, Both aplay or arecord reports
"Broken configuration for this PCM: no configurations available"!! for a wave file with channel_count '3'
ex: Playing WAVE './xxx.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Channels 3
ALSA lib pcm_params.c:2162:(snd1_pcm_hw_refine_slave) Slave PCM not usable
aplay: set_params:1204: Broken configuration for this PCM: no configurations available
With Following changes I was able to move ahead a bit:
.........................
Method1:
Driver is provided channel_count '3' as input via module parameter
Modified Driver to fill snd_pcm_hardware structure as payback->channels_min = 2 & playback->channels_min = 3; Similar values for capture path
aplay/arecord reports as 'channel count not available', though the wave file in use has 3 channels
ex: aplay -D hw:CARD=xxx,DEV=0 ./xxx.wav Playing WAVE './xxx.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Channels 3
aplay: set_params:1239: Channels count non available
Tried aplay/arecord with plughw, and aplay/arecord moved ahead
arecord -D plughw:CARD=xxx,DEV=0 -d 3 -f S16_LE -r 48000 -c 3 ./xxx_rec0.wav
aplay -D plughw:CARD=xxx,DEV=0 ./xxx.wav
Recording WAVE './xxx_rec0.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Channels 3
Playing WAVE './xxx.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Channels 3
End of Test
During aplay/arecord, In driver when "runtime->channels" value is checked it returns value 2!!! But played wavefile has ch count 3...
When data in recorded file is checked its all silence
.........................
Method2:
Driver is provided channel_count '3' as input via module parameter
Modified Driver to fill snd_pcm_hardware structure as playback->channels_min = 3 & playback->channels_min = 4; Similar values for capture path
aplay/arecord reports as 'channel count not available', though the wave file in use has 3 channels
Tried aplay/arecord with plughw, and aplay/arecord moved ahead
During aplay/arecord, In driver when "runtime->channels" value is checked it returns value 4!!! But played wavefile has ch count 3...
When data in recorded file is checked its all silence
.........................
So from above observations, the runtime->channels is either 2 or 4, but never 3 channels was used by alsa stack though requested. When used Plughw, alsa is converting data to run under 2 or 4 channel.
Can anyone help why am unable to use channel count 3.
Will provide more information if needed.
Thanks in Advance.
A period (and the entire buffer) must contain an integral number of frames, i.e., you cannot have partial frames.
With three channels, one frame has six bytes. The fixed period size (4096) is not divisible by six without remainder.
Thanks CL.
I used period size 4092 for this particular test case with channel count 3, and was able to do loop back successfully (without using plughw).
One last question, when I used plughw earlier, and when runtime->channels was either 2 or 4, why was the recorded data not showing?

GStreamer Custom-Plugin and alsasink Unable to Detect Format

I'm developing a GStreamer plugin following the GStreamer Plugin Writer's Guide and using gst-element-maker from the gst-plugins-bad repository with the base class set to basetransform. As a starting point I have developed a plugin named MyFilter that simply passes the data along the chain. The plugin is working, but when I run gst-launch with the debug level set to 2, I get the following error:
alsa gstalsa.c:124:gst_alsa_detect_formats: skipping non-int format.
I am executing the command:
gst-launch --gst-debug-level=2 --gst-plugin-load=./src/libgstmyfilter.la filesrc location=./song.mp3 ! flump3dec ! audioconvert ! audioresample ! myfilter ! alsasink
From the base class that was created by gst-element-maker I have removed calls to gst_pad_new_from_static_template() because the calls were returning errors reporting that the sink and source pad were already created, I have set the chain function using gst_pad_set_chain_function(), have implemented the function gst_myfilter_transform_caps(), and have added code to handle the GST_EVENT_NEWSEGMENT event. The STATIC_CAPS string I am using for source and sink are:
"audio/x-raw-int, "
"rate = (int) { 16000, 32000, 44100, 48000 }, "
"channels = (int) [ 1, 2 ], "
"endianness = (int) BYTE_ORDER, "
"signed = (boolean) true, "
"width = (int) 16, "
"depth = (int) 16"
I return the caps from gst_myfilter_transform_caps() using gst_pad_get_fixed_caps_func(GST_BASE_TRANSFORM_SRC[[/SINK]]_PAD(trans)). The pad caps are set using the default code created by gst-element-maker in gst_myfilter_base_init() using:
gst_element_class_add_pad_template(element_class, gst_static_pad_template_get(&gst_myfilter_sink_template));
Is there a problem with the GstBaseTransform class? I have another custom filter which does not use the GstBaseTransform class and does not have this problem. I am using GStreamer v0.10.36 with Ubuntu 12.04.

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