On Tue, Dec 23, 2008 at 9:12 AM, Sameer Naik <sameer.subscriptions at damagehead.com> wrote: > Hi, > I am writing a gstreamer plugin in which i need to calculate the raw audio > buffer size for a give sample rate, channels, etc. > > for example if i have a mp3 frame with the following parameters: > bitrate: 320Kbps > sampling rate: 48000Hz > Channels: 2 > > How can i calculate the buffer size that would be required by the output buffer > to store the raw decoded data for this frame? basically what is the formula > for this calculation? size = samples_per_frame * channels * width You give channels here, so that's easy. Width depends on the format you're decoding to - e.g. if you have 32 bit floating point samples, width is 4 (bytes). If you have 16 bit samples, it's 2. samples_per_frame is mp3-specific. It's either 1152 or 576, depending on the bitrate (and layer, and whether it's using the "mpeg 2.5" extensions. For 320 kbps mp3, it's 1152. So: size = 1152 * 2 * sample_width Mike
