mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-05 00:39:59 +00:00
685 lines
16 KiB
Go
685 lines
16 KiB
Go
package mp4
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"io"
|
|
|
|
"github.com/abema/go-mp4/internal/bitio"
|
|
)
|
|
|
|
type ProbeInfo struct {
|
|
MajorBrand [4]byte
|
|
MinorVersion uint32
|
|
CompatibleBrands [][4]byte
|
|
FastStart bool
|
|
Timescale uint32
|
|
Duration uint64
|
|
Tracks Tracks
|
|
Segments Segments
|
|
}
|
|
|
|
// Deprecated: replace with ProbeInfo
|
|
type FraProbeInfo = ProbeInfo
|
|
|
|
type Tracks []*Track
|
|
|
|
// Deprecated: replace with Track
|
|
type TrackInfo = Track
|
|
|
|
type Track struct {
|
|
TrackID uint32
|
|
Timescale uint32
|
|
Duration uint64
|
|
Codec Codec
|
|
Encrypted bool
|
|
EditList EditList
|
|
Samples Samples
|
|
Chunks Chunks
|
|
AVC *AVCDecConfigInfo
|
|
MP4A *MP4AInfo
|
|
}
|
|
|
|
type Codec int
|
|
|
|
const (
|
|
CodecUnknown Codec = iota
|
|
CodecAVC1
|
|
CodecMP4A
|
|
)
|
|
|
|
type EditList []*EditListEntry
|
|
|
|
type EditListEntry struct {
|
|
MediaTime int64
|
|
SegmentDuration uint64
|
|
}
|
|
|
|
type Samples []*Sample
|
|
|
|
type Sample struct {
|
|
Size uint32
|
|
TimeDelta uint32
|
|
CompositionTimeOffset int64
|
|
}
|
|
|
|
type Chunks []*Chunk
|
|
|
|
type Chunk struct {
|
|
DataOffset uint64
|
|
SamplesPerChunk uint32
|
|
}
|
|
|
|
type AVCDecConfigInfo struct {
|
|
ConfigurationVersion uint8
|
|
Profile uint8
|
|
ProfileCompatibility uint8
|
|
Level uint8
|
|
LengthSize uint16
|
|
Width uint16
|
|
Height uint16
|
|
}
|
|
|
|
type MP4AInfo struct {
|
|
OTI uint8
|
|
AudOTI uint8
|
|
ChannelCount uint16
|
|
}
|
|
|
|
type Segments []*Segment
|
|
|
|
// Deprecated: replace with Segment
|
|
type SegmentInfo = Segment
|
|
|
|
type Segment struct {
|
|
TrackID uint32
|
|
MoofOffset uint64
|
|
BaseMediaDecodeTime uint64
|
|
DefaultSampleDuration uint32
|
|
SampleCount uint32
|
|
Duration uint32
|
|
CompositionTimeOffset int32
|
|
Size uint32
|
|
}
|
|
|
|
// Probe probes MP4 file
|
|
func Probe(r io.ReadSeeker) (*ProbeInfo, error) {
|
|
probeInfo := &ProbeInfo{
|
|
Tracks: make([]*Track, 0, 8),
|
|
Segments: make([]*Segment, 0, 8),
|
|
}
|
|
bis, err := ExtractBoxes(r, nil, []BoxPath{
|
|
{BoxTypeFtyp()},
|
|
{BoxTypeMoov()},
|
|
{BoxTypeMoov(), BoxTypeMvhd()},
|
|
{BoxTypeMoov(), BoxTypeTrak()},
|
|
{BoxTypeMoof()},
|
|
{BoxTypeMdat()},
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
var mdatAppeared bool
|
|
for _, bi := range bis {
|
|
switch bi.Type {
|
|
case BoxTypeFtyp():
|
|
var ftyp Ftyp
|
|
if _, err := bi.SeekToPayload(r); err != nil {
|
|
return nil, err
|
|
}
|
|
if _, err := Unmarshal(r, bi.Size-bi.HeaderSize, &ftyp, bi.Context); err != nil {
|
|
return nil, err
|
|
}
|
|
probeInfo.MajorBrand = ftyp.MajorBrand
|
|
probeInfo.MinorVersion = ftyp.MinorVersion
|
|
probeInfo.CompatibleBrands = make([][4]byte, 0, len(ftyp.CompatibleBrands))
|
|
for _, entry := range ftyp.CompatibleBrands {
|
|
probeInfo.CompatibleBrands = append(probeInfo.CompatibleBrands, entry.CompatibleBrand)
|
|
}
|
|
case BoxTypeMoov():
|
|
probeInfo.FastStart = !mdatAppeared
|
|
case BoxTypeMvhd():
|
|
var mvhd Mvhd
|
|
if _, err := bi.SeekToPayload(r); err != nil {
|
|
return nil, err
|
|
}
|
|
if _, err := Unmarshal(r, bi.Size-bi.HeaderSize, &mvhd, bi.Context); err != nil {
|
|
return nil, err
|
|
}
|
|
probeInfo.Timescale = mvhd.Timescale
|
|
if mvhd.GetVersion() == 0 {
|
|
probeInfo.Duration = uint64(mvhd.DurationV0)
|
|
} else {
|
|
probeInfo.Duration = mvhd.DurationV1
|
|
}
|
|
case BoxTypeTrak():
|
|
track, err := probeTrak(r, bi)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
probeInfo.Tracks = append(probeInfo.Tracks, track)
|
|
case BoxTypeMoof():
|
|
segment, err := probeMoof(r, bi)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
probeInfo.Segments = append(probeInfo.Segments, segment)
|
|
case BoxTypeMdat():
|
|
mdatAppeared = true
|
|
}
|
|
}
|
|
return probeInfo, nil
|
|
}
|
|
|
|
// ProbeFra probes fragmented MP4 file
|
|
// Deprecated: replace with Probe
|
|
func ProbeFra(r io.ReadSeeker) (*FraProbeInfo, error) {
|
|
probeInfo, err := Probe(r)
|
|
return (*FraProbeInfo)(probeInfo), err
|
|
}
|
|
|
|
func probeTrak(r io.ReadSeeker, bi *BoxInfo) (*Track, error) {
|
|
track := new(Track)
|
|
|
|
bips, err := ExtractBoxesWithPayload(r, bi, []BoxPath{
|
|
{BoxTypeTkhd()},
|
|
{BoxTypeEdts(), BoxTypeElst()},
|
|
{BoxTypeMdia(), BoxTypeMdhd()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeAvc1()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeAvc1(), BoxTypeAvcC()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeEncv()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeEncv(), BoxTypeAvcC()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeMp4a()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeMp4a(), BoxTypeEsds()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeMp4a(), BoxTypeWave(), BoxTypeEsds()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeEnca()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsd(), BoxTypeEnca(), BoxTypeEsds()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStco()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeCo64()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStts()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeCtts()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsc()},
|
|
{BoxTypeMdia(), BoxTypeMinf(), BoxTypeStbl(), BoxTypeStsz()},
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
var tkhd *Tkhd
|
|
var elst *Elst
|
|
var mdhd *Mdhd
|
|
var avc1 *VisualSampleEntry
|
|
var avcC *AVCDecoderConfiguration
|
|
var audioSampleEntry *AudioSampleEntry
|
|
var esds *Esds
|
|
var stco *Stco
|
|
var stts *Stts
|
|
var stsc *Stsc
|
|
var ctts *Ctts
|
|
var stsz *Stsz
|
|
var co64 *Co64
|
|
for _, bip := range bips {
|
|
switch bip.Info.Type {
|
|
case BoxTypeTkhd():
|
|
tkhd = bip.Payload.(*Tkhd)
|
|
case BoxTypeElst():
|
|
elst = bip.Payload.(*Elst)
|
|
case BoxTypeMdhd():
|
|
mdhd = bip.Payload.(*Mdhd)
|
|
case BoxTypeAvc1():
|
|
track.Codec = CodecAVC1
|
|
avc1 = bip.Payload.(*VisualSampleEntry)
|
|
case BoxTypeAvcC():
|
|
avcC = bip.Payload.(*AVCDecoderConfiguration)
|
|
case BoxTypeEncv():
|
|
track.Codec = CodecAVC1
|
|
track.Encrypted = true
|
|
case BoxTypeMp4a():
|
|
track.Codec = CodecMP4A
|
|
audioSampleEntry = bip.Payload.(*AudioSampleEntry)
|
|
case BoxTypeEnca():
|
|
track.Codec = CodecMP4A
|
|
track.Encrypted = true
|
|
audioSampleEntry = bip.Payload.(*AudioSampleEntry)
|
|
case BoxTypeEsds():
|
|
esds = bip.Payload.(*Esds)
|
|
case BoxTypeStco():
|
|
stco = bip.Payload.(*Stco)
|
|
case BoxTypeStts():
|
|
stts = bip.Payload.(*Stts)
|
|
case BoxTypeStsc():
|
|
stsc = bip.Payload.(*Stsc)
|
|
case BoxTypeCtts():
|
|
ctts = bip.Payload.(*Ctts)
|
|
case BoxTypeStsz():
|
|
stsz = bip.Payload.(*Stsz)
|
|
case BoxTypeCo64():
|
|
co64 = bip.Payload.(*Co64)
|
|
}
|
|
}
|
|
|
|
if tkhd == nil {
|
|
return nil, errors.New("tkhd box not found")
|
|
}
|
|
track.TrackID = tkhd.TrackID
|
|
|
|
if elst != nil {
|
|
editList := make([]*EditListEntry, 0, len(elst.Entries))
|
|
for i := range elst.Entries {
|
|
editList = append(editList, &EditListEntry{
|
|
MediaTime: elst.GetMediaTime(i),
|
|
SegmentDuration: elst.GetSegmentDuration(i),
|
|
})
|
|
}
|
|
track.EditList = editList
|
|
}
|
|
|
|
if mdhd == nil {
|
|
return nil, errors.New("mdhd box not found")
|
|
}
|
|
track.Timescale = mdhd.Timescale
|
|
track.Duration = mdhd.GetDuration()
|
|
|
|
if avc1 != nil && avcC != nil {
|
|
track.AVC = &AVCDecConfigInfo{
|
|
ConfigurationVersion: avcC.ConfigurationVersion,
|
|
Profile: avcC.Profile,
|
|
ProfileCompatibility: avcC.ProfileCompatibility,
|
|
Level: avcC.Level,
|
|
LengthSize: uint16(avcC.LengthSizeMinusOne) + 1,
|
|
Width: avc1.Width,
|
|
Height: avc1.Height,
|
|
}
|
|
}
|
|
|
|
if audioSampleEntry != nil && esds != nil {
|
|
oti, audOTI, err := detectAACProfile(esds)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
track.MP4A = &MP4AInfo{
|
|
OTI: oti,
|
|
AudOTI: audOTI,
|
|
ChannelCount: audioSampleEntry.ChannelCount,
|
|
}
|
|
}
|
|
|
|
track.Chunks = make([]*Chunk, 0)
|
|
if stco != nil {
|
|
for _, offset := range stco.ChunkOffset {
|
|
track.Chunks = append(track.Chunks, &Chunk{
|
|
DataOffset: uint64(offset),
|
|
})
|
|
}
|
|
} else if co64 != nil {
|
|
for _, offset := range co64.ChunkOffset {
|
|
track.Chunks = append(track.Chunks, &Chunk{
|
|
DataOffset: offset,
|
|
})
|
|
}
|
|
} else {
|
|
return nil, errors.New("stco/co64 box not found")
|
|
}
|
|
|
|
if stts == nil {
|
|
return nil, errors.New("stts box not found")
|
|
}
|
|
track.Samples = make([]*Sample, 0)
|
|
for _, entry := range stts.Entries {
|
|
for i := uint32(0); i < entry.SampleCount; i++ {
|
|
track.Samples = append(track.Samples, &Sample{
|
|
TimeDelta: entry.SampleDelta,
|
|
})
|
|
}
|
|
}
|
|
|
|
if stsc == nil {
|
|
return nil, errors.New("stsc box not found")
|
|
}
|
|
for si, entry := range stsc.Entries {
|
|
end := uint32(len(track.Chunks))
|
|
if si != len(stsc.Entries)-1 && stsc.Entries[si+1].FirstChunk-1 < end {
|
|
end = stsc.Entries[si+1].FirstChunk - 1
|
|
}
|
|
for ci := entry.FirstChunk - 1; ci < end; ci++ {
|
|
track.Chunks[ci].SamplesPerChunk = entry.SamplesPerChunk
|
|
}
|
|
}
|
|
|
|
if ctts != nil {
|
|
var si uint32
|
|
for ci, entry := range ctts.Entries {
|
|
for i := uint32(0); i < entry.SampleCount; i++ {
|
|
if si >= uint32(len(track.Samples)) {
|
|
break
|
|
}
|
|
track.Samples[si].CompositionTimeOffset = ctts.GetSampleOffset(ci)
|
|
si++
|
|
}
|
|
}
|
|
}
|
|
|
|
if stsz != nil {
|
|
for i := 0; i < len(stsz.EntrySize) && i < len(track.Samples); i++ {
|
|
track.Samples[i].Size = stsz.EntrySize[i]
|
|
}
|
|
}
|
|
|
|
return track, nil
|
|
}
|
|
|
|
func detectAACProfile(esds *Esds) (oti, audOTI uint8, err error) {
|
|
configDscr := findDescriptorByTag(esds.Descriptors, DecoderConfigDescrTag)
|
|
if configDscr == nil || configDscr.DecoderConfigDescriptor == nil {
|
|
return 0, 0, nil
|
|
}
|
|
if configDscr.DecoderConfigDescriptor.ObjectTypeIndication != 0x40 {
|
|
return configDscr.DecoderConfigDescriptor.ObjectTypeIndication, 0, nil
|
|
}
|
|
|
|
specificDscr := findDescriptorByTag(esds.Descriptors, DecSpecificInfoTag)
|
|
if specificDscr == nil {
|
|
return 0, 0, errors.New("DecoderSpecificationInfoDescriptor not found")
|
|
}
|
|
|
|
r := bitio.NewReader(bytes.NewReader(specificDscr.Data))
|
|
remaining := len(specificDscr.Data) * 8
|
|
|
|
// audio object type
|
|
audioObjectType, read, err := getAudioObjectType(r)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= read
|
|
|
|
// sampling frequency index
|
|
samplingFrequencyIndex, err := r.ReadBits(4)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= 4
|
|
if samplingFrequencyIndex[0] == 0x0f {
|
|
if _, err = r.ReadBits(24); err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= 24
|
|
}
|
|
|
|
if audioObjectType == 2 && remaining >= 20 {
|
|
if _, err = r.ReadBits(4); err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= 4
|
|
syncExtensionType, err := r.ReadBits(11)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= 11
|
|
if syncExtensionType[0] == 0x2 && syncExtensionType[1] == 0xb7 {
|
|
extAudioObjectType, _, err := getAudioObjectType(r)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
if extAudioObjectType == 5 || extAudioObjectType == 22 {
|
|
sbr, err := r.ReadBits(1)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining--
|
|
if sbr[0] != 0 {
|
|
if extAudioObjectType == 5 {
|
|
sfi, err := r.ReadBits(4)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= 4
|
|
if sfi[0] == 0xf {
|
|
if _, err := r.ReadBits(24); err != nil {
|
|
return 0, 0, err
|
|
}
|
|
remaining -= 24
|
|
}
|
|
if remaining >= 12 {
|
|
syncExtensionType, err := r.ReadBits(11)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
if syncExtensionType[0] == 0x5 && syncExtensionType[1] == 0x48 {
|
|
ps, err := r.ReadBits(1)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
if ps[0] != 0 {
|
|
return 0x40, 29, nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return 0x40, 5, nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return 0x40, audioObjectType, nil
|
|
}
|
|
|
|
func findDescriptorByTag(dscrs []Descriptor, tag int8) *Descriptor {
|
|
for _, dscr := range dscrs {
|
|
if dscr.Tag == tag {
|
|
return &dscr
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func getAudioObjectType(r bitio.Reader) (byte, int, error) {
|
|
audioObjectType, err := r.ReadBits(5)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
if audioObjectType[0] != 0x1f {
|
|
return audioObjectType[0], 5, nil
|
|
}
|
|
audioObjectType, err = r.ReadBits(6)
|
|
if err != nil {
|
|
return 0, 0, err
|
|
}
|
|
return audioObjectType[0] + 32, 11, nil
|
|
}
|
|
|
|
func probeMoof(r io.ReadSeeker, bi *BoxInfo) (*Segment, error) {
|
|
bips, err := ExtractBoxesWithPayload(r, bi, []BoxPath{
|
|
{BoxTypeTraf(), BoxTypeTfhd()},
|
|
{BoxTypeTraf(), BoxTypeTfdt()},
|
|
{BoxTypeTraf(), BoxTypeTrun()},
|
|
})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
var tfhd *Tfhd
|
|
var tfdt *Tfdt
|
|
var trun *Trun
|
|
|
|
segment := &Segment{
|
|
MoofOffset: bi.Offset,
|
|
}
|
|
for _, bip := range bips {
|
|
switch bip.Info.Type {
|
|
case BoxTypeTfhd():
|
|
tfhd = bip.Payload.(*Tfhd)
|
|
case BoxTypeTfdt():
|
|
tfdt = bip.Payload.(*Tfdt)
|
|
case BoxTypeTrun():
|
|
trun = bip.Payload.(*Trun)
|
|
}
|
|
}
|
|
|
|
if tfhd == nil {
|
|
return nil, errors.New("tfhd not found")
|
|
}
|
|
segment.TrackID = tfhd.TrackID
|
|
segment.DefaultSampleDuration = tfhd.DefaultSampleDuration
|
|
|
|
if tfdt != nil {
|
|
if tfdt.Version == 0 {
|
|
segment.BaseMediaDecodeTime = uint64(tfdt.BaseMediaDecodeTimeV0)
|
|
} else {
|
|
segment.BaseMediaDecodeTime = tfdt.BaseMediaDecodeTimeV1
|
|
}
|
|
}
|
|
|
|
if trun != nil {
|
|
segment.SampleCount = trun.SampleCount
|
|
|
|
if trun.CheckFlag(0x000100) {
|
|
segment.Duration = 0
|
|
for ei := range trun.Entries {
|
|
segment.Duration += trun.Entries[ei].SampleDuration
|
|
}
|
|
} else {
|
|
segment.Duration = tfhd.DefaultSampleDuration * segment.SampleCount
|
|
}
|
|
|
|
if trun.CheckFlag(0x000200) {
|
|
segment.Size = 0
|
|
for ei := range trun.Entries {
|
|
segment.Size += trun.Entries[ei].SampleSize
|
|
}
|
|
} else {
|
|
segment.Size = tfhd.DefaultSampleSize * segment.SampleCount
|
|
}
|
|
|
|
var duration uint32
|
|
for ei := range trun.Entries {
|
|
offset := int32(duration) + int32(trun.GetSampleCompositionTimeOffset(ei))
|
|
if ei == 0 || offset < segment.CompositionTimeOffset {
|
|
segment.CompositionTimeOffset = offset
|
|
}
|
|
if trun.CheckFlag(0x000100) {
|
|
duration += trun.Entries[ei].SampleDuration
|
|
} else {
|
|
duration += tfhd.DefaultSampleDuration
|
|
}
|
|
}
|
|
}
|
|
|
|
return segment, nil
|
|
}
|
|
|
|
func FindIDRFrames(r io.ReadSeeker, trackInfo *TrackInfo) ([]int, error) {
|
|
if trackInfo.AVC == nil {
|
|
return nil, nil
|
|
}
|
|
lengthSize := uint32(trackInfo.AVC.LengthSize)
|
|
|
|
var si int
|
|
idxs := make([]int, 0, 8)
|
|
for _, chunk := range trackInfo.Chunks {
|
|
end := si + int(chunk.SamplesPerChunk)
|
|
dataOffset := chunk.DataOffset
|
|
for ; si < end && si < len(trackInfo.Samples); si++ {
|
|
sample := trackInfo.Samples[si]
|
|
if sample.Size == 0 {
|
|
continue
|
|
}
|
|
for nalOffset := uint32(0); nalOffset+lengthSize+1 <= sample.Size; {
|
|
if _, err := r.Seek(int64(dataOffset+uint64(nalOffset)), io.SeekStart); err != nil {
|
|
return nil, err
|
|
}
|
|
data := make([]byte, lengthSize+1)
|
|
if _, err := io.ReadFull(r, data); err != nil {
|
|
return nil, err
|
|
}
|
|
var length uint32
|
|
for i := 0; i < int(lengthSize); i++ {
|
|
length = (length << 8) + uint32(data[i])
|
|
}
|
|
nalHeader := data[lengthSize]
|
|
nalType := nalHeader & 0x1f
|
|
if nalType == 5 {
|
|
idxs = append(idxs, si)
|
|
break
|
|
}
|
|
nalOffset += lengthSize + length
|
|
}
|
|
dataOffset += uint64(sample.Size)
|
|
}
|
|
}
|
|
return idxs, nil
|
|
}
|
|
|
|
func (samples Samples) GetBitrate(timescale uint32) uint64 {
|
|
var totalSize uint64
|
|
var totalDuration uint64
|
|
for _, sample := range samples {
|
|
totalSize += uint64(sample.Size)
|
|
totalDuration += uint64(sample.TimeDelta)
|
|
}
|
|
if totalDuration == 0 {
|
|
return 0
|
|
}
|
|
return 8 * totalSize * uint64(timescale) / totalDuration
|
|
}
|
|
|
|
func (samples Samples) GetMaxBitrate(timescale uint32, timeDelta uint64) uint64 {
|
|
if timeDelta == 0 {
|
|
return 0
|
|
}
|
|
var maxBitrate uint64
|
|
var size uint64
|
|
var duration uint64
|
|
var begin int
|
|
var end int
|
|
for end < len(samples) {
|
|
for {
|
|
size += uint64(samples[end].Size)
|
|
duration += uint64(samples[end].TimeDelta)
|
|
end++
|
|
if duration >= timeDelta || end == len(samples) {
|
|
break
|
|
}
|
|
}
|
|
bitrate := 8 * size * uint64(timescale) / duration
|
|
if bitrate > maxBitrate {
|
|
maxBitrate = bitrate
|
|
}
|
|
for {
|
|
size -= uint64(samples[begin].Size)
|
|
duration -= uint64(samples[begin].TimeDelta)
|
|
begin++
|
|
if duration < timeDelta {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
return maxBitrate
|
|
}
|
|
|
|
func (segments Segments) GetBitrate(trackID uint32, timescale uint32) uint64 {
|
|
var totalSize uint64
|
|
var totalDuration uint64
|
|
for _, segment := range segments {
|
|
if segment.TrackID == trackID {
|
|
totalSize += uint64(segment.Size)
|
|
totalDuration += uint64(segment.Duration)
|
|
}
|
|
}
|
|
if totalDuration == 0 {
|
|
return 0
|
|
}
|
|
return 8 * totalSize * uint64(timescale) / totalDuration
|
|
}
|
|
|
|
func (segments Segments) GetMaxBitrate(trackID uint32, timescale uint32) uint64 {
|
|
var maxBitrate uint64
|
|
for _, segment := range segments {
|
|
if segment.TrackID == trackID && segment.Duration != 0 {
|
|
bitrate := 8 * uint64(segment.Size) * uint64(timescale) / uint64(segment.Duration)
|
|
if bitrate > maxBitrate {
|
|
maxBitrate = bitrate
|
|
}
|
|
}
|
|
}
|
|
return maxBitrate
|
|
}
|