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feat(xgplayer-transmuxer): MP4格式支持解析matrix、rotation

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liujing.cyan 2024-06-17 20:22:39 +08:00 committed by gemstone
parent 685f04fd3f
commit fb7fbb73e2
2 changed files with 46 additions and 4 deletions
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39
packages/xgplayer-transmuxer/src/mp4/mp4-parser.js
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@ -1,5 +1,5 @@
import { AudioCodecType, VideoCodecType } from '../model'
import { getAvcCodec, readBig16, readBig24, readBig32, readBig64 } from '../utils'
import { getAvcCodec, readBig16, readBig24, readBig32, readBig64, combineToFloat, toDegree } from '../utils'
import { AAC } from '../codec'
export class MP4Parser {
static findBox (data, names, start = 0) {
@ -126,15 +126,26 @@ export class MP4Parser {
return parseBox(box, true, (ret, data) => {
let start = 0
if (ret.version === 1) {
ret.createTime = readBig64(data, 0)
ret.modifyTime = readBig64(data, 8)
ret.timescale = readBig32(data, 16)
ret.duration = readBig64(data, 20)
start += 28
} else {
ret.createTime = readBig32(data, 0)
ret.modifyTime = readBig32(data, 4)
ret.timescale = readBig32(data, 8)
ret.duration = readBig32(data, 12)
start += 16
}
ret.nextTrackId = readBig32(data, start + 76)
ret.rate = combineToFloat(readBig16(data, start), readBig16(data, start + 2))
start += 4
ret.volume = combineToFloat(data[start], data[start + 1])
start += 2
start += 10 // skip
start += 36 // skip matrix, Because the rotate of the mp4 video track is determined by the matrix in tkhd box
start += 24 // skip
ret.nextTrackId = readBig32(data, start)
})
}
@ -157,8 +168,26 @@ export class MP4Parser {
ret.duration = readBig32(data, 16)
start += 20
}
ret.width = readBig32(data, start + 52)
ret.height = readBig32(data, start + 56)
start += 8 // skip
ret.layer = readBig16(data, start)
start += 2
ret.alternateGroup = readBig16(data, start)
start += 2
start += 4 // skip
ret.matrix = [] // for remux
for (let i = 0; i < 36; i++) {
ret.matrix.push(data[start + i])
}
const caculatedMatrix = [] // for caculation of rotation
for (let i = 0; i < 9; i++) {
caculatedMatrix.push(combineToFloat(readBig16(data, start + i * 2), readBig16(data, start + i * 2 + 2))) // 16.16 fixed point
caculatedMatrix.push(combineToFloat(readBig16(data, start + i * 2 + 4), readBig16(data, start + i * 2 + 6))) // 16.16 fixed point
caculatedMatrix.push(combineToFloat(data[start + i * 2 + 8] & 0x3, readBig32(data, start + i * 2 + 8) >>> 2)) // 2.30 fixed point
}
start += 36
ret.rotation = toDegree(caculatedMatrix)
ret.width = readBig32(data, start) // 16.16 fixed point, no parsed
ret.height = readBig32(data, start + 4) // 16.16 fixed point, no parsed
})
}
@ -767,6 +796,8 @@ export class MP4Parser {
v.mvhdTimecale = moov.mvhd.timescale
v.timescale = v.formatTimescale = vTrack.mdia.mdhd.timescale
v.duration = vTrack.mdia.mdhd.duration || (v.mvhdDurtion / v.mvhdTimecale * v.timescale)
v.rotation = vTrack.tkhd.rotation
v.matrix = vTrack.tkhd.matrix
const e1 = vTrack.mdia.minf.stbl.stsd.entries[0]
v.width = e1.width
v.height = e1.height

11
packages/xgplayer-transmuxer/src/utils/index.js
View File

@ -87,3 +87,14 @@ export function hashVal (str) {
}
return hash
}
export function combineToFloat (integer, decimal) {
return Number(integer + '.' + decimal)
}
export function toDegree (matrix) {
if (matrix.length < 5)
return 0
const scaled0 = Math.hypot(matrix[0], matrix[3]), scaled1 = Math.hypot(matrix[1], matrix[4])
return 0 === scaled0 || 0 === scaled1 ? 0 : 180 * Math.atan2(matrix[1] / scaled1, matrix[0] / scaled0) / Math.PI
}