Go back 3 seconds from any point in the video

[EmJayEm]

I'm using the GPAC tools (OSMO4, mp4box) to create a mpeg4 file.

I want to be able to jump back 3 seconds in a video by pressing a button while the video is playing. I have tried editing some of the GPAC Regression Test examples to achieve this but I am having no luck. This is what I did:

Created a 'jump' button:

Transform2D {
translation 50 -65
children [
DEF TS4 TouchSensor {}
Shape {
appearance Appearance {
material DEF M33 Material2D {
emissiveColor 0 1 0
filled TRUE
}
}
geometry Circle {
radius 15
}
}
Transform2D {
children [
Shape {
appearance USE TXTAPP
geometry Text {
string ["Jump"]
fontStyle USE FS
}
}
]
}
]
}

Used a script node to jump back 3 seconds in the video.

DEF SC Script {
url "javascript:
function jump_time(value) {
if (value)
ctrl.mediaStartTime = ctrl.mediaStartTime -3.0;
}

"
eventIn SFBool jump_time
field SFNode ctrl USE MC
}

Then used a route to link the button to the script node:

ROUTE TS4.isActive TO SC.jump_time


Here is the complete code:


InitialObjectDescriptor {
objectDescriptorID 1
audioProfileLevelIndication 255
visualProfileLevelIndication 254
sceneProfileLevelIndication 1
graphicsProfileLevelIndication 1
ODProfileLevelIndication 1
esDescr [
ES_Descriptor {
ES_ID 1
decConfigDescr DecoderConfigDescriptor {
streamType 3
decSpecificInfo BIFSConfig {
isCommandStream true
pixelMetric true
pixelWidth 300
pixelHeight 200
}
}
}
ES_Descriptor {
ES_ID 2
decConfigDescr DecoderConfigDescriptor {
streamType 1
}
}
]
}

OrderedGroup {
children [
Background2D {
backColor 1 1 1
}
WorldInfo {
info ["This shows MediaControl" "controling video playback speed" "" "GPAC Regression Tests" "(C) 2002-2004 GPAC Team"]
title "Media Control Test"
}
DEF MC MediaControl {
url [od:8]
loop TRUE
}
Transform2D {
translation -100 -65
children [
DEF TS1 TouchSensor {}
Shape {
appearance Appearance {
material DEF M1 Material2D {
emissiveColor 1 0 0
filled TRUE
}
}
geometry Circle {
radius 30
}
}
Transform2D {
children [
Shape {
appearance DEF TXTAPP Appearance {
material Material2D {
emissiveColor 0 0 0
filled TRUE
}
}
geometry Text {
string ["Speed" "x4"]
fontStyle DEF FS FontStyle {
justify ["MIDDLE" "MIDDLE"]
size 18
}
}
}
]
}
]
}
Transform2D {
translation 100 -65
children [
DEF TS2 TouchSensor {}
Shape {
appearance Appearance {
material DEF M2 Material2D {
emissiveColor 0 0 1
filled TRUE
}
}
geometry Circle {
radius 30
}
}
Transform2D {
children [
Shape {
appearance USE TXTAPP
geometry Text {
string ["Speed" "x0.5"]
fontStyle USE FS
}
}
]
}
]
}
Transform2D {
translation 0 -65
children [
DEF TS3 TouchSensor {}
Shape {
appearance Appearance {
material DEF M3 Material2D {
emissiveColor 0 1 0
filled TRUE
}
}
geometry Circle {
radius 30
}
}
Transform2D {
children [
Shape {
appearance USE TXTAPP
geometry Text {
string ["Mute"]
fontStyle USE FS
}
}
]
}
]
}
Transform2D {
translation 50 -65
children [
DEF TS4 TouchSensor {}
Shape {
appearance Appearance {
material DEF M33 Material2D {
emissiveColor 0 1 0
filled TRUE
}
}
geometry Circle {
radius 15
}
}
Transform2D {
children [
Shape {
appearance USE TXTAPP
geometry Text {
string ["Jump"]
fontStyle USE FS
}
}
]
}
]
}
Transform2D {
translation 0 30
children [
Shape {
appearance Appearance {
texture MovieTexture {
url [od:8]
}
}
geometry Bitmap {}

}
]
}
DEF C1 Conditional {
buffer {
REPLACE MC.mediaSpeed BY 4
REPLACE M1.emissiveColor BY 1 0.5 0.5
}
}
DEF C2 Conditional {
buffer {
REPLACE MC.mediaSpeed BY 0.5
REPLACE M2.emissiveColor BY 0.5 0.5 1
}
}
DEF C3 Conditional {
buffer {
REPLACE MC.mute BY TRUE
REPLACE M3.emissiveColor BY 0.5 1 0.5
}
}
DEF RESET Conditional {
buffer {
REPLACE MC.mediaSpeed BY 1
REPLACE MC.mute BY FALSE
REPLACE M1.emissiveColor BY 1 0 0
REPLACE M2.emissiveColor BY 0 0 1
REPLACE M3.emissiveColor BY 0 1 0
}
}
DEF SC Script {
url "javascript:
function jump_time(value) {
if (value)
ctrl.mediaStartTime = 3.0;
}

"
eventIn SFBool jump_time
field SFNode ctrl USE MC
}



]
}

ROUTE TS1.isOver TO C1.activate
ROUTE TS1.isOver TO RESET.reverseActivate
ROUTE TS2.isOver TO C2.activate
ROUTE TS2.isOver TO RESET.reverseActivate
ROUTE TS3.isOver TO C3.activate
ROUTE TS3.isOver TO RESET.reverseActivate
ROUTE TS4.isActive TO SC.jump_time

AT 0 {
UPDATE OD [
ObjectDescriptor {
objectDescriptorID 8
esDescr [
ES_Descriptor {
ES_ID 21
OCR_ES_ID 21
muxInfo MuxInfo {
fileName "streams/video_small.media"
}
}
]
}
]
}


Does anyone know where I am going wrong with this?

Thanks,

EmJ.


PS. Bond, I like mp4menu!

[EmJayEm]

OK, now I have acheived what I wanted to acheive, here is the code:

InitialObjectDescriptor {
objectDescriptorID 1
audioProfileLevelIndication 255
visualProfileLevelIndication 254
sceneProfileLevelIndication 1
graphicsProfileLevelIndication 1
ODProfileLevelIndication 1
esDescr [
ES_Descriptor {
ES_ID 1
decConfigDescr DecoderConfigDescriptor {
streamType 3
decSpecificInfo BIFSConfig {
isCommandStream true
pixelMetric true
pixelWidth 300
pixelHeight 200
}
}
}
ES_Descriptor {
ES_ID 2
decConfigDescr DecoderConfigDescriptor {
streamType 1
}
}
]
}

OrderedGroup {
children [
Background2D {
backColor 1 1 1
}
WorldInfo {
info ["This shows MediaControl" "controling video playback speed" "" "GPAC Regression Tests" "(C) 2002-2004 GPAC Team"]
title "Media Control Test"
}
DEF MC MediaControl {
url [od:8]
loop TRUE
preRoll FALSE
}
DEF MS MediaSensor {
url [od:8]
}
Transform2D {
translation 50 -65
children [
DEF TS4 TouchSensor {}
Shape {
appearance Appearance {
material DEF ME Material2D {
emissiveColor 0 1 0
filled TRUE
}
}
geometry Circle {
radius 15
}
}

]
}
Transform2D {
translation 0 -65
children [
DEF TS2 TouchSensor {}
Shape {
appearance Appearance {
material DEF ME Material2D {
emissiveColor 0 1 1
filled TRUE
}
}
geometry Circle {
radius 15
}
}

]
}
Transform2D {
translation 0 30
children [
Shape {
appearance Appearance {
texture MovieTexture {
url [od:8]
}
}
geometry Bitmap {}

}
]
}
DEF SC Script {
url "javascript:
function jump_time(value) {
if (value)
{ctrl.mediaStartTime = medias.mediaCurrentTime+0.5;}
}
function jump_timet(value) {
if (!value)
{if(medias.mediaCurrentTime>5){ctrl.mediaStartTime = 0;}}
}
function jump_back(value) {
if (value)
{ctrl.mediaStartTime = medias.mediaCurrentTime-0.5;}
}


"
eventIn SFBool jump_time
eventIn SFBool jump_timet
eventIn SFBool jump_back
field SFNode ctrl USE MC
field SFNode medias USE MS
field SFTime curSeek 0
}



]
}

ROUTE TS4.isActive TO SC.jump_time
ROUTE TS4.isActive TO SC.jump_timet
ROUTE TS2.isActive TO SC.jump_back

AT 0 {
UPDATE OD [
ObjectDescriptor {
objectDescriptorID 8
esDescr [
ES_Descriptor {
ES_ID 21
OCR_ES_ID 21
muxInfo MuxInfo {
fileName "streams/video_small.media"
}
}
]
}
]
}

[bond]

cool stuff :)