Read the frame data out of the CMSampleBuffer

Still not sending it anywhere, but think I'm reading it correctly.

crates/capture/Cargo.toml

@@ -4,10 +4,6 @@ version = "0.1.0"
 edition = "2021"
 description = "An example of screen capture"
 
-[package.metadata.bundle]
-name = "Capture"
-identifier = "dev.zed.Capture"
-
 [dependencies]
 gpui = { path = "../gpui" }
 media = { path = "../media" }
@@ -15,6 +11,7 @@ media = { path = "../media" }
 anyhow = "1.0.38"
 block = "0.1"
 bytes = "1.2"
+byteorder = "1.4"
 cocoa = "0.24"
 core-foundation = "0.9.3"
 core-graphics = "0.22.3"

crates/capture/script/capture

@@ -1,5 +0,0 @@
-#!/bin/bash
-
-cargo bundle
-TTY=`tty`
-open ../../target/debug/bundle/osx/Capture.app --stdout $TTY --stderr $TTY

crates/capture/src/main.rs

@@ -3,6 +3,7 @@ mod compression_session;
 
 use crate::{bindings::SCStreamOutputType, compression_session::CompressionSession};
 use block::ConcreteBlock;
+use byteorder::{BigEndian, ReadBytesExt};
 use bytes::BytesMut;
 use cocoa::{
     base::{id, nil, YES},
@@ -128,6 +129,25 @@ impl ScreenCaptureView {
                                 let nal_unit = compression_buffer.split();
                             }
                         }
+
+                        let data = sample_buffer.data();
+                        let mut data = data.bytes();
+
+                        const AVCC_HEADER_LENGTH: usize = 4;
+                        while data.len() - AVCC_HEADER_LENGTH > 0 {
+                            let nal_unit_len = match data.read_u32::<BigEndian>() {
+                                Ok(len) => len as usize,
+                                Err(error) => {
+                                    log::error!("error decoding nal unit length: {}", error);
+                                    return;
+                                }
+                            };
+                            compression_buffer.extend_from_slice(&START_CODE);
+                            compression_buffer.extend_from_slice(&data[..nal_unit_len as usize]);
+                            data = &data[nal_unit_len..];
+
+                            let nal_unit = compression_buffer.split();
+                        }
                     },
                 )
                 .unwrap();