Des del 2000 compartiendo sobre…

Tag: audio

How to get MP3 file from a WebM video

Reading time: < 1 minute Another title for this post could be: "Getting audio from video clips". Because you could do it with MP4 (Mpeg4), WebM, Mov, FLV, etc. We are going to use ffmpeg to that:

ffmpeg -i input_file.webm -ab 128k -ar 44100 out_file.mp3

The meaning of the parameters:

  • ab: the audio bitrate in bps
  • ar: the audio sample rate in hz

And if you have a directory with a lot of files to convert you could use:

find . -name "*.webm" -print0 |while read -d $'\0' file; do ffmpeg -i "$file" -ab 128k -ar 44100 -y "${file%.webm}.mp3";done

Pay attention to “find” and “while read” commands combinations because we want to support files with spaces.

I hope this is as useful for you as for me.

Microfon intern del Dell XPS m1330 funciona amb Linux

Reading time: < 1 minute No m'havia posat a provar mai el microfon intern del portàtil ja que sempre havia llegit que no funcionava. Però ahir vaig actualitzar el kernel a la verisó 2.6.25-gentoo-r5 i hem vaig decidir a provar a veure què tal. Doncs bé la veritat és que oli en un llum. Ja que només he hagut de canviar la font d’entrada de gravacions i ha funcionat a la primera així és com l’he de deixar:

gnome volume manager

La veritat és que he tingut molta sort 😉

Pioneer MT-01 – Power Line Sound System

Reading time: 2 – 2 minutes

Pioneer ha presentat un sistema de fins a 6 altaveus que distribueixen el so a través de la línia elèctrica. O sigui, un complement ideal per l’invent del mpd que vaig explicar fa uns mesos. Els altaveus poden ser de dos tipus de 5W o 25W. Estèticament realment els trobo molt atractius.


A més disposa d’algunes funcionalitat força espectaculars com al d’un detector de moviment que activa l’altaveu quan entrem en una habitació. A més de disposar d’un comandament a distància que ens permet escollir en cada altaveu alguna de les dues possibles fonts d’audio seleccionables que té. Realment sembla molt ben acabat el producte.

El model és el MT-01
i incorpora de serie dos altaveus un de 25W i un de 5W, el comandament a distància i la unitat central. A part, com ja deia es podem comprar fins a 6 altaveus en total combinant indiferenment els de 5 o 25W. La unitat central diposa de 5 entrades diferents: USB (tipus A i B), entrada d’audio frontal i dues entrades analògiques, diferents entrades de memòries flash.

Sobre el tema del preu que és el més preocupant no en sé res, a més tampoc tinc dades de si mai s’arribarà a vendre al nostre país de moment només ho he vist a anglaterra.

Neuros OSD – free your media

Reading time: 3 – 5 minutes

Un altre producte a l’estil del Chumby:

The Neuros OSD was created to connect user’s computer and entertainment worlds. Among many other things, this would allow users to watch video downloads and digital photo slideshows on TVs and listen to MP3s through their stereos. Previously the choices for doing this have been restricted to two approaches: all-in-one PC-based media centers and limited, closed “embedded” devices in various forms: PVRs, digital media adapters and streaming devices.


The OSD also enables users to take their video on the go and watch video on any device with non-DRM, standard MPEG-4 files. The OSD supports virtually all devices with data conversion or requiring extensive set-up. There are no subscription fees associated with the use of the OSD.


The OSD enables all of the above by combining many of the attributes of PCs and embedded devices in a single device.

Like a PC, the OSD is open, expandable, flexible and standard and uses software that is upgradeable and relentlessly enhanced. By taking these attributes and applying them to an “embedded” consumer electronics device, the OSD can evolve and grow to meet all the expanding needs of the digital consumer in a device that, unlike a PC, is small, inexpensive, silent, and designed specifically for the job.

The Neuros OSD runs Linux with a USB host, built-in networking, and IR blaster. It has a dual core processor from TI that was designed specifically for multi-media applications and can encode and playback full DVD resolution MPEG-4 and play virtually all forms of digital audio and pictures. It connects directly to different accessories like iPods, USB webcameras, external DVD drives, and external hard drives. It also records onto memory cards for easy transfer to PSPs, smartphones, and other non-USB portables.

In short, the Neuros OSD contains the essence of what consumers want in a device to bridge their computer, home A/V systems, and portables without the baggage of a legacy PC system.

  • MPEG4 encoding and decoding (as many formats and wrappers as possible) – D1 (720×480)resolution at 30 fps
  • MPEG2 encoding and decoding
  • Ethernet
  • Linux (2.6 Kernel)
  • Dual Core Processor ARM9/TI DSP
  • SD/CF/MS card slots
  • USB host
  • IR Blaster
  • IR remote

The front of the device has the following I/O:

  • IR receiver
  • USB Host
  • Multi-card (SD/MS/MS PRO/MS DUO/MMC)
  • Compact Flash (including microdrive)
  • Dual color LED (green and Red)

The back of the device has the following I/O:

  • Power
  • Serial connector (to conrol tuner boxes and connection to PC for developer debugging)
  • IR Blaster (for controlling tuner boxes)
  • S-Video input
  • Ethernet 10/100
  • Composite Audio and Video input and output (RCA connector cables included)

NOTA aquest post esta escrit a basa de copy/paste del wiki de Neuros OSD.

A linuxdevices hi ha un bon review sobre el Nueros OSD, es pot ampliar detalls des d’allà.