sunlubo
121 lines
3.0 KiB
Swift
121 lines
3.0 KiB
Swift
//
|
|
// encode_video.swift
|
|
// Demo
|
|
//
|
|
// Created by sunlubo on 2018/7/3.
|
|
//
|
|
|
|
import SwiftFFmpeg
|
|
|
|
#if canImport(Darwin)
|
|
import Darwin
|
|
#else
|
|
import Glibc
|
|
#endif
|
|
|
|
private func encode(
|
|
codecCtx: AVCodecContext,
|
|
frame: AVFrame?,
|
|
pkt: AVPacket,
|
|
file: UnsafeMutablePointer<FILE>
|
|
) throws {
|
|
if let frame = frame {
|
|
print(String(format: "Send frame %3d", frame.pts))
|
|
}
|
|
|
|
// send the frame to the encoder
|
|
try codecCtx.sendFrame(frame)
|
|
|
|
while true {
|
|
do {
|
|
try codecCtx.receivePacket(pkt)
|
|
} catch let err as AVError where err == .tryAgain || err == .eof {
|
|
return
|
|
}
|
|
|
|
print(String(format: "Write packet %3d (size=%5d)", pkt.pts, pkt.size))
|
|
|
|
fwrite(pkt.data, 1, pkt.size, file)
|
|
|
|
pkt.unref()
|
|
}
|
|
}
|
|
|
|
func encode_video() throws {
|
|
if CommandLine.argc < 3 {
|
|
print("Usage: \(CommandLine.arguments[0]) \(CommandLine.arguments[1]) output_file")
|
|
return
|
|
}
|
|
|
|
let output = CommandLine.arguments[2]
|
|
// find the mpeg1video encoder
|
|
let codec = AVCodec.findEncoderByName("mpeg1video")!
|
|
let codecCtx = AVCodecContext(codec: codec)
|
|
|
|
// put sample parameters
|
|
codecCtx.bitRate = 400000
|
|
// resolution must be a multiple of two
|
|
codecCtx.width = 352
|
|
codecCtx.height = 288
|
|
// frames per second
|
|
codecCtx.timebase = AVRational(num: 1, den: 25)
|
|
codecCtx.framerate = AVRational(num: 25, den: 1)
|
|
// emit one intra frame every ten frames
|
|
// check frame pict_type before passing frame
|
|
// to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
|
|
// then gop_size is ignored and the output of encoder
|
|
// will always be I frame irrespective to gop_size
|
|
codecCtx.gopSize = 10
|
|
codecCtx.maxBFrames = 1
|
|
codecCtx.pixelFormat = .YUV420P
|
|
|
|
try codecCtx.openCodec()
|
|
|
|
guard let file = fopen(output, "wb") else {
|
|
fatalError("Could not open \(output)")
|
|
}
|
|
defer { fclose(file) }
|
|
|
|
let pkt = AVPacket()
|
|
let frame = AVFrame()
|
|
frame.pixelFormat = codecCtx.pixelFormat
|
|
frame.width = codecCtx.width
|
|
frame.height = codecCtx.height
|
|
|
|
try frame.allocBuffer(align: 32)
|
|
|
|
// encode 1 second of video
|
|
for i in 0..<25 {
|
|
// make sure the frame data is writable
|
|
try frame.makeWritable()
|
|
|
|
// prepare a dummy image
|
|
// Y
|
|
for y in 0..<codecCtx.height {
|
|
for x in 0..<codecCtx.width {
|
|
frame.data[0]![y * Int(frame.linesize[0]) + x] = UInt8(truncatingIfNeeded: x + y + i * 3)
|
|
}
|
|
}
|
|
|
|
// Cb and Cr
|
|
for y in 0..<codecCtx.height / 2 {
|
|
for x in 0..<codecCtx.width / 2 {
|
|
frame.data[1]![y * Int(frame.linesize[1]) + x] = UInt8(truncatingIfNeeded: 128 + y + i * 2)
|
|
frame.data[2]![y * Int(frame.linesize[2]) + x] = UInt8(truncatingIfNeeded: 64 + x + i * 5)
|
|
}
|
|
}
|
|
|
|
frame.pts = Int64(i)
|
|
|
|
// encode the image
|
|
try encode(codecCtx: codecCtx, frame: frame, pkt: pkt, file: file)
|
|
}
|
|
|
|
// flush the encoder
|
|
try encode(codecCtx: codecCtx, frame: nil, pkt: pkt, file: file)
|
|
|
|
// add sequence end code to have a real MPEG file
|
|
let endcode = [0, 0, 1, 0xb7] as [UInt8]
|
|
fwrite(endcode, 1, endcode.count, file)
|
|
}
|