Author Topic: Download a 64 kbps Podcast at 384 kbps using FFMPEG  (Read 280 times)

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Offline Ed

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Download a 64 kbps Podcast at 384 kbps using FFMPEG
« on: July 11, 2017, 04:47:12 PM »
Whilst listening to a "Listen Again" radio show on BBC iPlayer, I noticed that it had a button marked DOWNLOAD. This was the first time I'd seen such an option on iPlayer.

Turns out it's a fairly common feature on science programmes (I was listening to a broadcast about botany), albeit one which is completely unknown on Light Entertainment programmes. (This may tell you more about me than about the iPlayer!)

Investigating further, I discovered that it is what the BBC term a 'podcast'. They define this as being an mp3 file, recorded at 64 kbps, downloadable on demand. Probably, therefore, everything I'm about to mention will apply to all BBC podcasts.

You've opened this thread because of what you read in its title, so it won't surprise you to learn that I'm about to describe a method for violating the 64 kbps limitation, and instead downloading the podcast of interest at the standard on-demand bitrate of 384 kbps.

Software required -

FFMPEG.exe (Static build recommended)

Procedure -

1.  Create a batch file (a plain-text file with the extension .bat or .cmd)
     (name it, say, download.bat).
2.  Put FFMPEG.exe in the same directory/folder as the batch file.
3.  Copy-and-paste the command line, below, into the batch file (for this,
     open the batch file in a text editor, e.g. Notepad, not a word processor).
4.  Then save the file (be sure to save it with the extension .bat not .txt).
5.  (Optional) Modify the file extension specified on the command line:
     change it from .mp2 to whatever you want (only mp2 gives 384 kbps output).
6.  Copy-and-paste into the batch file the url address of the mp3 podcast file
     (found by right-clicking on the podcast's "Download" button).
7.  Run the batch file.

Here is the command line for Step 3 (actually, 2 lines), which you copy-and-paste into the batch file:

Code: [Select]
SET url=

ffmpeg  -v 16  -stats  -i  %url%  output.mp2

In Step 6, when you copy-and-paste the url address into the batch file, the SET command should resemble this example (I've added colours: the part in silver is the part you insert) -

SET url=

Important:  Do not modify the url address. Although it is an mp3 address, and you aim to download an mp2 file, it is essential that the target url is EXACTLY the same as the iPlayer page specifies. My command line, above, handles the necessary technical jiggery-pokery.

The above method should be capable of downloading any podcast that does not use DRM (but I've never come across a DRM podcast on the BBC site). What you get for your trouble is a download of the podcast show, at 384 kbps, as a 44.1kHz mp2 file (instead of as 64 kbps 44.1kHz mp3).

Technical Note

On the 'Listen Again' service, FFMPEG fetches whichever audio stream you specify.

If the command line specifies .mp2 the program will fetch the .mp2 stream (which, on BBC iPlayer, is a 384 kbps stream); or if the command line specifies .m4a the program will fetch the .m4a stream (which, on BBC iPlayer, is a 128 kbps stream).

There are lots of different file types (e.g. .mp3, .mp2, .m4a, .mp4, .mpeg, .ts, .flac, .wav). FFmpeg will fetch a different stream (i.e. a different bitrate and/or sample rate) for each of the different file types.

The highest bitrate is for uncompressed .wav (approx 1,500 kbps). The highest bitrate I've yet come across for a compressed format is 384 kbps for the .mp2 file type.

« Last Edit: July 11, 2017, 06:40:59 PM by Ed »