| |
| |
|
|
| use base64::Engine; |
| use base64::engine::general_purpose::STANDARD as BASE64_STANDARD; |
| use codex_protocol::models::MAX_PROMPT_AUDIO_INPUT_BYTES; |
|
|
| pub(super) fn wav_duration_seconds(audio_url: &str) -> Option<f64> { |
| let (metadata, payload) = audio_url.split_once(',')?; |
| if !metadata |
| .split(';') |
| .skip(1) |
| .any(|part| part.eq_ignore_ascii_case("base64")) |
| || payload.len() > MAX_PROMPT_AUDIO_INPUT_BYTES.div_ceil(3) * 4 |
| { |
| return None; |
| } |
| let bytes = BASE64_STANDARD.decode(payload).ok()?; |
| if bytes.get(..4)? != b"RIFF" || bytes.get(8..12)? != b"WAVE" { |
| return None; |
| } |
|
|
| let mut chunks = bytes.get(12..)?; |
| let mut format = None; |
| while chunks.len() >= 8 { |
| let chunk_id = &chunks[..4]; |
| let size = u32::from_le_bytes(chunks[4..8].try_into().ok()?) as usize; |
| let remaining = &chunks[8..]; |
| |
| let chunk = &remaining[..size.min(remaining.len())]; |
| match chunk_id { |
| b"fmt " => { |
| let mut encoding = u16::from_le_bytes(chunk.get(..2)?.try_into().ok()?); |
| if encoding == 0xfffe { |
| |
| if chunk.get(26..40)? |
| != [0, 0, 0, 0, 0x10, 0, 0x80, 0, 0, 0xaa, 0, 0x38, 0x9b, 0x71] |
| { |
| return None; |
| } |
| encoding = u16::from_le_bytes(chunk.get(24..26)?.try_into().ok()?); |
| } |
| if !matches!(encoding, 1 | 3) { |
| return None; |
| } |
| let sample_rate = u32::from_le_bytes(chunk.get(4..8)?.try_into().ok()?); |
| let block_align = u16::from_le_bytes(chunk.get(12..14)?.try_into().ok()?); |
| if sample_rate == 0 || block_align == 0 { |
| return None; |
| } |
| format = Some((sample_rate, block_align)); |
| } |
| b"data" => { |
| let (sample_rate, block_align) = format?; |
| let frames = chunk.len() / usize::from(block_align); |
| return Some(frames as f64 / f64::from(sample_rate)); |
| } |
| _ => {} |
| } |
| chunks = remaining.get(size.checked_add(size % 2)?..)?; |
| } |
| None |
| } |
|
|
