When I was younger I would listen to music recorded on my phone from the radio. They were 128 kb/s, which sounds OK until you see they’re .wav files so they don’t use the bitrate effectively: just mono, 32kHz sample rate, 4 bits per sample. They sound worse than 24 kb/s MP3s, which is something you’d stream over a 28k modem in 1999!
(The SoC can and does do AMR compression when recording MPEG-4 (more specifically 3GP4, which uses MPEG-4 part 2, not the well-known AVC, which is MPEG-4 part 10) video but the manufacturer just didn’t take advantage of it, maybe the library for video recording was proprietary and the AMR codec not well documented.)
Do you realize that 4 bits per sample has a theoretical maximum S/N ratio of some 24 dB? That’s 10x the noise amplitude of the worst tapes. Not even Audacity wil let you create files that crappy. Not to mention I often recorded in a bus, resulting in extra noise and dropouts.
I used to use teletext but what is teletext radio? The bitrate of VBI is way more enough than audio but I couldn’t find any information about it being used that way…
I mean, when browsing teletext with your decoder you’d get the TV channel’s audio unless you muted it. Did you mean “teletext demo” programs that didn’t require decoders and were often broadcast just before signoff? In Czechoslovakia before 24-hour TV, we’d get classical music, signoff, the anthem (pre-1989), and then a test pattern with a radio station. Video of this
I’d imagine some teletext demo programs did have radio playing.
When I was younger I would listen to music recorded on my phone from the radio. They were 128 kb/s, which sounds OK until you see they’re .wav files so they don’t use the bitrate effectively: just mono, 32kHz sample rate, 4 bits per sample. They sound worse than 24 kb/s MP3s, which is something you’d stream over a 28k modem in 1999!
(The SoC can and does do AMR compression when recording MPEG-4 (more specifically 3GP4, which uses MPEG-4 part 2, not the well-known AVC, which is MPEG-4 part 10) video but the manufacturer just didn’t take advantage of it, maybe the library for video recording was proprietary and the AMR codec not well documented.)
Things are better now, mostly.
I used to record songs from the TV and TELETEXT “radio”… to tape.
Do you realize that 4 bits per sample has a theoretical maximum S/N ratio of some 24 dB? That’s 10x the noise amplitude of the worst tapes. Not even Audacity wil let you create files that crappy. Not to mention I often recorded in a bus, resulting in extra noise and dropouts.
I used to use teletext but what is teletext radio? The bitrate of VBI is way more enough than audio but I couldn’t find any information about it being used that way…
Sometimes there was music in the background, some sort of radio. Don’t stress over it, that was not a technical endeavor.
I mean, when browsing teletext with your decoder you’d get the TV channel’s audio unless you muted it. Did you mean “teletext demo” programs that didn’t require decoders and were often broadcast just before signoff? In Czechoslovakia before 24-hour TV, we’d get classical music, signoff, the anthem (pre-1989), and then a test pattern with a radio station. Video of this
I’d imagine some teletext demo programs did have radio playing.