add adjust-speed operation, refactor

README.md

@@ -106,6 +106,10 @@ test suite.
 ### [add-silence](src/test/resources/tests/test_add_silence.jvc)
 Add a silent audio track to a video asset.
 
+### [adjust-speed](src/test/resources/tests/test_adjust_speed.jvc)
+Speed up or slow down a video asset. Sound can be silenced, played at
+regular speed, or sped up along with the video.
+
 ### [concat](src/test/resources/tests/test_concat.jvc)
 Concatenate audio/video assets together into one asset.
 

bin/jspeed

@@ -0,0 +1,43 @@
+#!/bin/bash
+#
+# Adjust the speed of a video, optionally adjusting the audio as well.
+#
+# Usage:
+#
+#    jspeed in-file out-file speed-factor [audio-speed]
+#
+# in-file       : input video file
+# out-file      : write output file here
+# speed-factor  : factor=1 is unchanged, factor>1 is faster, factor<1 is slower
+# audio-speed   : can be: silent (default), unchanged, or match
+#
+# Note: if audio-speed is match, then speed-factor must be between 0.5 and 100
+#
+SCRIPT="${0}"
+SCRIPT_DIR="$(cd "$(dirname "${SCRIPT}")" && pwd)"
+. "${SCRIPT_DIR}"/jvc_common
+
+IN_FILE="${1?no video-file provided}"
+OUT_FILE="${2?no out-file provided}"
+SPEED_FACTOR="${3?no speed-factor provided}"
+AUDIO_SPEED="${4}"
+
+echo "
+{
+  \"assets\": [
+    { \"name\": \"input\", \"path\": \"${IN_FILE}\" }
+  ],
+  \"operations\": [
+    {
+      \"operation\": \"adjust-speed\",
+      \"creates\": {
+        \"name\": \"speed_adjusted\",
+        \"dest\": \"${OUT_FILE}\"
+      },
+      \"source\": \"input\",
+      \"factor\": \"${SPEED_FACTOR}\"$(if [[ -n "${AUDIO_SPEED}" ]] ; then echo ",
+      \"audio\": \"${AUDIO_SPEED}\"" ; fi)
+    }
+  ]
+}
+" | "${SCRIPT_DIR}"/jvc ${JVC_OPTIONS}

docs/complex_example.md

@@ -198,6 +198,16 @@ support a `comment` field, which can be used as well.
       "source": "v2",                  // main video asset
       "channelLayout": "stereo",       // optional channel layout, usually 'mono' or 'stereo'. Default is 'stereo'
       "samplingRate": 48000            // optional sampling rate, in Hz. default is 48000
+    },
+
+    // adjust-speed example
+    {
+        "operation": "adjust-speed",     // name of the operation
+        "creates": "quickened",          // output asset name
+        "source": "v2",                  // main video asset
+        "factor": "4",                   // factor=1 is no change, factor>1 is faster, factor<1 is slower
+        "audio": "silent"                // audio: silent (default), unchanged, match
+                                         // if audio is match, then factor must be between 0.5 and 100
     }
   ]
 }

src/main/java/jvc/model/operation/JMultiOperationContext.java

@@ -2,6 +2,8 @@ package jvc.model.operation;
 
 import jvc.model.JAsset;
 import jvc.model.JFileExtension;
+import jvc.service.AssetManager;
+import jvc.service.Toolbox;
 import lombok.NoArgsConstructor;
 
 import java.util.List;
@@ -11,8 +13,12 @@ public class JMultiOperationContext extends JOperationContextBase {
 
     public List<JAsset> sources;
 
-    public JMultiOperationContext(List<JAsset> sources, JAsset output, JFileExtension formatType) {
-        super(output, formatType);
+    public JMultiOperationContext(List<JAsset> sources,
+                                  JAsset output,
+                                  JFileExtension formatType,
+                                  AssetManager assetManager,
+                                  Toolbox toolbox) {
+        super(output, formatType, assetManager, toolbox);
         this.sources = sources;
     }
 }

src/main/java/jvc/model/operation/JMultiSourceOperation.java

@@ -3,6 +3,7 @@ package jvc.model.operation;
 import jvc.model.JAsset;
 import jvc.model.JFileExtension;
 import jvc.service.AssetManager;
+import jvc.service.Toolbox;
 import lombok.Getter;
 import lombok.Setter;
 
@@ -17,7 +18,7 @@ public abstract class JMultiSourceOperation extends JOperation {
 
     @Getter @Setter private String[] sources;
 
-    public JMultiOperationContext getMultiInputContext(AssetManager assetManager) {
+    public JMultiOperationContext getMultiInputContext(AssetManager assetManager, Toolbox toolbox) {
         // validate sources
         final List<JAsset> sources = flattenAssetList(assetManager.resolve(getSources()));
         if (empty(sources)) die("operate: no sources");
@@ -31,6 +32,6 @@ public abstract class JMultiSourceOperation extends JOperation {
         // set the path, check if output asset already exists
         final JFileExtension formatType = output.getFormat().getFileExtension();
 
-        return new JMultiOperationContext(sources, output, formatType);
+        return new JMultiOperationContext(sources, output, formatType, assetManager, toolbox);
     }
 }

src/main/java/jvc/model/operation/JOperationContextBase.java

@@ -2,6 +2,8 @@ package jvc.model.operation;
 
 import jvc.model.JAsset;
 import jvc.model.JFileExtension;
+import jvc.service.AssetManager;
+import jvc.service.Toolbox;
 import lombok.AllArgsConstructor;
 import lombok.NoArgsConstructor;
 
@@ -10,5 +12,7 @@ public class JOperationContextBase {
 
     public JAsset output;
     public JFileExtension formatType;
+    public AssetManager assetManager;
+    public Toolbox toolbox;
 
 }

src/main/java/jvc/model/operation/JSingleOperationContext.java

@@ -2,6 +2,8 @@ package jvc.model.operation;
 
 import jvc.model.JAsset;
 import jvc.model.JFileExtension;
+import jvc.service.AssetManager;
+import jvc.service.Toolbox;
 import lombok.AllArgsConstructor;
 import lombok.NoArgsConstructor;
 
@@ -10,8 +12,12 @@ public class JSingleOperationContext extends JOperationContextBase {
     
     public JAsset source;
 
-    public JSingleOperationContext(JAsset source, JAsset output, JFileExtension formatType) {
-        super(output, formatType);
+    public JSingleOperationContext(JAsset source,
+                                   JAsset output,
+                                   JFileExtension formatType,
+                                   AssetManager assetManager,
+                                   Toolbox toolbox) {
+        super(output, formatType, assetManager, toolbox);
         this.source = source;
     }
 

src/main/java/jvc/model/operation/JSingleSourceOperation.java

@@ -5,6 +5,7 @@ import jvc.model.JFileExtension;
 import jvc.model.JFormat;
 import jvc.model.info.JTrackType;
 import jvc.service.AssetManager;
+import jvc.service.Toolbox;
 import lombok.Getter;
 import lombok.Setter;
 
@@ -18,7 +19,7 @@ public class JSingleSourceOperation extends JOperation {
 
     protected JTrackType outputMediaType() { return video; }
 
-    public JSingleOperationContext getSingleInputContext(AssetManager assetManager) {
+    public JSingleOperationContext getSingleInputContext(AssetManager assetManager, Toolbox toolbox) {
         final JAsset source = assetManager.resolve(getSource());
         final JAsset output = json2asset(getCreates());
         output.mergeFormat(source.getFormat());
@@ -35,7 +36,7 @@ public class JSingleSourceOperation extends JOperation {
         }
         final JFileExtension formatType = getFileExtension(source, output);
 
-        return new JSingleOperationContext(source, output, formatType);
+        return new JSingleOperationContext(source, output, formatType, assetManager, toolbox);
     }
 
     protected JFileExtension getFileExtension(JAsset source, JAsset output) {

src/main/java/jvc/operation/AdjustSpeedOperation.java

@@ -0,0 +1,29 @@
+package jvc.operation;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import jvc.model.operation.JSingleSourceOperation;
+import lombok.Getter;
+import lombok.Setter;
+import org.cobbzilla.util.javascript.JsEngine;
+
+import java.math.BigDecimal;
+import java.util.Map;
+
+import static java.math.BigDecimal.ONE;
+import static jvc.service.Toolbox.evalBig;
+
+public class AdjustSpeedOperation extends JSingleSourceOperation {
+
+    @Getter @Setter private String factor;
+    public BigDecimal getFactor(Map<String, Object> ctx, JsEngine js) {
+        return evalBig(factor, ctx, js, ONE);
+    }
+
+    @Getter @Setter private AudioSpeed audio = AudioSpeed.silent;
+
+    public enum AudioSpeed {
+        silent, unchanged, match;
+        @JsonCreator public static AudioSpeed fromString (String val) { return valueOf(val.toLowerCase()); }
+    }
+
+}

src/main/java/jvc/operation/exec/AddSilenceExec.java

@@ -1,14 +1,10 @@
 package jvc.operation.exec;
 
 import jvc.model.JAsset;
-import jvc.model.JFileExtension;
 import jvc.model.operation.JSingleOperationContext;
 import jvc.operation.AddSilenceOperation;
-import jvc.service.AssetManager;
-import jvc.service.Toolbox;
 import lombok.extern.slf4j.Slf4j;
 
-import java.util.HashMap;
 import java.util.Map;
 
 @Slf4j
@@ -21,20 +17,12 @@ public class AddSilenceExec extends SingleOrMultiSourceExecBase<AddSilenceOperat
 
     @Override protected String getProcessTemplate() { return ADD_SILENCE_TEMPLATE; }
 
-    @Override public void operate(AddSilenceOperation op, Toolbox toolbox, AssetManager assetManager) {
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
+    @Override protected void addCommandContext(AddSilenceOperation op,
+                                               JSingleOperationContext opCtx,
+                                               Map<String, Object> ctx) {
         final JAsset source = opCtx.source;
-        final JAsset output = opCtx.output;
-        final JFileExtension formatType = opCtx.formatType;
-
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
-
-        final JAsset silence = createSilence(op, toolbox, assetManager, source.duration(), source);
+        final JAsset silence = createSilence(op, opCtx.toolbox, opCtx.assetManager, source.duration(), source);
         ctx.put("silence", silence);
-
-        operate(op, toolbox, assetManager, source, output, formatType, ctx);
     }
 
 }

src/main/java/jvc/operation/exec/AdjustSpeedExec.java

@@ -0,0 +1,50 @@
+package jvc.operation.exec;
+
+import jvc.model.operation.JSingleOperationContext;
+import jvc.operation.AdjustSpeedOperation;
+import lombok.extern.slf4j.Slf4j;
+import org.cobbzilla.util.javascript.StandardJsEngine;
+
+import java.math.BigDecimal;
+import java.util.Map;
+
+import static java.math.BigDecimal.ONE;
+import static java.math.RoundingMode.HALF_EVEN;
+import static jvc.operation.AdjustSpeedOperation.AudioSpeed.match;
+import static org.cobbzilla.util.daemon.ZillaRuntime.big;
+import static org.cobbzilla.util.daemon.ZillaRuntime.die;
+
+@Slf4j
+public class AdjustSpeedExec extends SingleOrMultiSourceExecBase<AdjustSpeedOperation> {
+
+    public static final BigDecimal MINIMUM_ATEMPO = big(0.5);
+    public static final BigDecimal MAXIMUM_ATEMPO = big(100);
+
+    public static final String ADJUST_SPEED_TEMPLATE
+            = "{{{ffmpeg}}} -i {{{source.path}}} "
+            + "-filter_complex \""
+            + "[0:v]setpts={{inverseFactor}}*PTS[v]{{#if match}};[0:a]atempo={{factor}}[a]{{/if}}"
+            + "\" "
+            + "-map \"[v]\" "
+            + "{{#if silent}}-an{{else}}-map \"[a]\"{{/if}} "
+            + "-y {{{output.path}}}";
+
+    @Override protected String getProcessTemplate() { return ADJUST_SPEED_TEMPLATE; }
+
+    @Override protected void addCommandContext(AdjustSpeedOperation op,
+                                               JSingleOperationContext opCtx,
+                                               Map<String, Object> ctx) {
+        final StandardJsEngine js = opCtx.toolbox.getJs();
+        final BigDecimal factor = op.getFactor(ctx, js);
+
+        ctx.put(op.getAudio().name(), true);
+        if (op.getAudio() == match) {
+            if (factor.compareTo(MINIMUM_ATEMPO) < 0) die("addCommandContext: atempo cannot be less than "+MINIMUM_ATEMPO);
+            if (factor.compareTo(MAXIMUM_ATEMPO) > 0) die("addCommandContext: atempo cannot be greater than "+MAXIMUM_ATEMPO);
+        }
+        final BigDecimal inverseFactor = ONE.divide(factor, 8, HALF_EVEN);
+        ctx.put("factor", factor);
+        ctx.put("inverseFactor", inverseFactor);
+    }
+
+}

src/main/java/jvc/operation/exec/ConcatExec.java

@@ -33,7 +33,7 @@ public class ConcatExec extends ExecBase<ConcatOperation> {
 
     @Override public void operate(ConcatOperation op, Toolbox toolbox, AssetManager assetManager) {
 
-        final JMultiOperationContext opCtx = op.getMultiInputContext(assetManager);
+        final JMultiOperationContext opCtx = op.getMultiInputContext(assetManager, toolbox);
         final List<JAsset> sources = opCtx.sources;
         final JAsset output = opCtx.output;
         final JFileExtension formatType = opCtx.formatType;

src/main/java/jvc/operation/exec/ExecBase.java

@@ -42,6 +42,13 @@ public abstract class ExecBase<OP extends JOperation> {
         }
     }
 
+    protected Map<String, Object> initialContext(Toolbox toolbox, JAsset source) {
+        final Map<String, Object> ctx = new HashMap<>();
+        ctx.put("ffmpeg", toolbox.getFfmpeg());
+        ctx.put("source", source);
+        return ctx;
+    }
+
     public String exec(String script, boolean noExec) {
         if (noExec) {
             System.out.println(script);

src/main/java/jvc/operation/exec/KenBurnsExec.java

@@ -12,7 +12,6 @@ import org.cobbzilla.util.javascript.StandardJsEngine;
 
 import java.io.File;
 import java.math.BigDecimal;
-import java.util.HashMap;
 import java.util.Map;
 
 import static java.math.BigDecimal.ONE;
@@ -42,7 +41,7 @@ public class KenBurnsExec extends ExecBase<KenBurnsOperation> {
 
     @Override public void operate(KenBurnsOperation op, Toolbox toolbox, AssetManager assetManager) {
 
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
+        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager, toolbox);
         final JAsset source = opCtx.source;
         final JAsset output = opCtx.output;
         final JFileExtension formatType = opCtx.formatType;
@@ -53,9 +52,7 @@ public class KenBurnsExec extends ExecBase<KenBurnsOperation> {
         output.setPath(abs(path));
 
         final StandardJsEngine js = toolbox.getJs();
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
+        final Map<String, Object> ctx = initialContext(toolbox, source);
         ctx.put("output", output);
         ctx.put("width", op.getWidth(ctx, js));
         ctx.put("height", op.getHeight(ctx, js));

src/main/java/jvc/operation/exec/LetterboxExec.java

@@ -1,15 +1,10 @@
 package jvc.operation.exec;
 
-import jvc.model.JAsset;
-import jvc.model.JFileExtension;
 import jvc.model.operation.JSingleOperationContext;
 import jvc.operation.LetterboxOperation;
-import jvc.service.AssetManager;
-import jvc.service.Toolbox;
 import lombok.extern.slf4j.Slf4j;
 import org.cobbzilla.util.javascript.StandardJsEngine;
 
-import java.util.HashMap;
 import java.util.Map;
 
 import static org.cobbzilla.util.daemon.ZillaRuntime.die;
@@ -32,21 +27,13 @@ public class LetterboxExec extends SingleOrMultiSourceExecBase<LetterboxOperatio
 
     @Override protected String getProcessTemplate() { return LETTERBOX_TEMPLATE; }
 
-    @Override public void operate(LetterboxOperation op, Toolbox toolbox, AssetManager assetManager) {
-
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
-        final JAsset source = opCtx.source;
-        final JAsset output = opCtx.output;
-        final JFileExtension formatType = opCtx.formatType;
-
-        final StandardJsEngine js = toolbox.getJs();
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
-
+    @Override protected void addCommandContext(LetterboxOperation op,
+                                               JSingleOperationContext opCtx,
+                                               Map<String, Object> ctx) {
         if (!op.hasWidth() || !op.hasHeight()) {
             die("operate: both width and height must be set");
         }
+        final StandardJsEngine js = opCtx.toolbox.getJs();
         ctx.put("width", op.getWidth(ctx, js).intValue());
         ctx.put("height", op.getHeight(ctx, js).intValue());
 
@@ -55,8 +42,5 @@ public class LetterboxExec extends SingleOrMultiSourceExecBase<LetterboxOperatio
         } else {
             ctx.put("color", DEFAULT_LETTERBOX_COLOR);
         }
-
-        operate(op, toolbox, assetManager, source, output, formatType, ctx);
     }
-
 }

src/main/java/jvc/operation/exec/MergeAudioExec.java

@@ -35,30 +35,18 @@ public class MergeAudioExec extends SingleOrMultiSourceExecBase<MergeAudioOperat
 
     @Override protected String getProcessTemplate() { return MERGE_AUDIO_TEMPLATE; }
 
-    @Override public void operate(MergeAudioOperation op, Toolbox toolbox, AssetManager assetManager) {
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
-        final JAsset source = opCtx.source;
-        final JAsset output = opCtx.output;
-        final JFileExtension formatType = opCtx.formatType;
-
-        final JAsset audio = assetManager.resolve(op.getInsert());
-
-        final StandardJsEngine js = toolbox.getJs();
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
-        ctx.put("audio", audio);
-
+    @Override
+    protected void addCommandContext(MergeAudioOperation op, JSingleOperationContext opCtx, Map<String, Object> ctx) {
+        final JAsset audio = opCtx.assetManager.resolve(op.getInsert());
+        final StandardJsEngine js = opCtx.toolbox.getJs();
         final BigDecimal insertAt = op.getAt(ctx, js);
         ctx.put("start", insertAt);
 
         if (insertAt.compareTo(ZERO) > 0) {
-            final JAsset silence = createSilence(op, toolbox, assetManager, insertAt, audio);
-            final JAsset padded = padWithSilence(op, toolbox, assetManager, audio, silence);
+            final JAsset silence = createSilence(op, opCtx.toolbox, opCtx.assetManager, insertAt, audio);
+            final JAsset padded = padWithSilence(op, opCtx.toolbox, opCtx.assetManager, audio, silence);
             ctx.put("audio", padded);
         }
-
-        operate(op, toolbox, assetManager, source, output, formatType, ctx);
     }
 
     protected JAsset padWithSilence(MergeAudioOperation op,

src/main/java/jvc/operation/exec/OverlayExec.java

@@ -11,7 +11,6 @@ import org.cobbzilla.util.javascript.StandardJsEngine;
 
 import java.io.File;
 import java.math.BigDecimal;
-import java.util.HashMap;
 import java.util.Map;
 
 import static org.cobbzilla.util.io.FileUtil.abs;
@@ -27,7 +26,7 @@ public class OverlayExec extends ExecBase<OverlayOperation> {
 
     @Override public void operate(OverlayOperation op, Toolbox toolbox, AssetManager assetManager) {
 
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
+        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager, toolbox);
         final JAsset source = opCtx.source;
         final JAsset output = opCtx.output;
         final JFileExtension formatType = opCtx.formatType;
@@ -41,9 +40,7 @@ public class OverlayExec extends ExecBase<OverlayOperation> {
         output.setPath(abs(path));
 
         final StandardJsEngine js = toolbox.getJs();
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
+        final Map<String, Object> ctx = initialContext(toolbox, source);
         ctx.put("overlay", overlaySource);
 
         ctx.put("mainStart", op.getStartTime(ctx, js));

src/main/java/jvc/operation/exec/RemoveTrackExec.java

@@ -1,16 +1,11 @@
 package jvc.operation.exec;
 
-import jvc.model.JAsset;
-import jvc.model.JFileExtension;
 import jvc.model.JTrackId;
 import jvc.model.info.JTrackType;
 import jvc.model.operation.JSingleOperationContext;
 import jvc.operation.RemoveTrackOperation;
-import jvc.service.AssetManager;
-import jvc.service.Toolbox;
 import lombok.extern.slf4j.Slf4j;
 
-import java.util.HashMap;
 import java.util.Map;
 
 @Slf4j
@@ -24,23 +19,13 @@ public class RemoveTrackExec extends SingleOrMultiSourceExecBase<RemoveTrackOper
 
     @Override protected String getProcessTemplate() { return REMOVE_TRACK_TEMPLATE; }
 
-    @Override public void operate(RemoveTrackOperation op, Toolbox toolbox, AssetManager assetManager) {
-
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
-        final JAsset source = opCtx.source;
-        final JAsset output = opCtx.output;
-        final JFileExtension formatType = opCtx.formatType;
-
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
-
+    @Override protected void addCommandContext(RemoveTrackOperation op,
+                                               JSingleOperationContext opCtx,
+                                               Map<String, Object> ctx) {
         final JTrackId trackId = op.getTrackId();
         final JTrackType trackType = trackId.getType();
         ctx.put("trackType", trackType.ffmpegType());
         if (trackId.hasNumber()) ctx.put("trackNumber", trackId.getNumber());
-
-        operate(op, toolbox, assetManager, source, output, formatType, ctx);
     }
 
 }

src/main/java/jvc/operation/exec/ScaleExec.java

@@ -1,16 +1,12 @@
 package jvc.operation.exec;
 
 import jvc.model.JAsset;
-import jvc.model.JFileExtension;
 import jvc.model.operation.JSingleOperationContext;
 import jvc.operation.ScaleOperation;
-import jvc.service.AssetManager;
-import jvc.service.Toolbox;
 import lombok.extern.slf4j.Slf4j;
 import org.cobbzilla.util.javascript.StandardJsEngine;
 
 import java.math.BigDecimal;
-import java.util.HashMap;
 import java.util.Map;
 
 @Slf4j
@@ -23,17 +19,11 @@ public class ScaleExec extends SingleOrMultiSourceExecBase<ScaleOperation> {
 
     @Override protected String getProcessTemplate() { return SCALE_TEMPLATE; }
 
-    @Override public void operate(ScaleOperation op, Toolbox toolbox, AssetManager assetManager) {
-
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
+    @Override protected void addCommandContext(ScaleOperation op,
+                                               JSingleOperationContext opCtx,
+                                               Map<String, Object> ctx) {
+        final StandardJsEngine js = opCtx.toolbox.getJs();
         final JAsset source = opCtx.source;
-        final JAsset output = opCtx.output;
-        final JFileExtension formatType = opCtx.formatType;
-
-        final StandardJsEngine js = toolbox.getJs();
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-
         if (op.hasFactor()) {
             final BigDecimal factor = op.getFactor(ctx, js);
             ctx.put("width", factor.multiply(source.getWidth()).intValue());
@@ -41,8 +31,6 @@ public class ScaleExec extends SingleOrMultiSourceExecBase<ScaleOperation> {
         } else {
             op.setProportionalWidthAndHeight(ctx, js, source);
         }
-
-        operate(op, toolbox, assetManager, source, output, formatType, ctx);
     }
 
 }

src/main/java/jvc/operation/exec/SingleOrMultiSourceExecBase.java

@@ -2,7 +2,8 @@ package jvc.operation.exec;
 
 import jvc.model.JAsset;
 import jvc.model.JFileExtension;
-import jvc.model.operation.JOperation;
+import jvc.model.operation.JSingleOperationContext;
+import jvc.model.operation.JSingleSourceOperation;
 import jvc.service.AssetManager;
 import jvc.service.Toolbox;
 import lombok.extern.slf4j.Slf4j;
@@ -14,7 +15,19 @@ import static org.cobbzilla.util.daemon.ZillaRuntime.die;
 import static org.cobbzilla.util.io.FileUtil.*;
 
 @Slf4j
-public abstract class SingleOrMultiSourceExecBase<OP extends JOperation> extends ExecBase<OP> {
+public abstract class SingleOrMultiSourceExecBase<OP extends JSingleSourceOperation> extends ExecBase<OP> {
+
+    @Override public void operate(OP op, Toolbox toolbox, AssetManager assetManager) {
+        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager, toolbox);
+        final JAsset source = opCtx.source;
+        final JAsset output = opCtx.output;
+        final JFileExtension formatType = opCtx.formatType;
+        final Map<String, Object> ctx = initialContext(toolbox, source);
+        addCommandContext(op, opCtx, ctx);
+        operate(op, toolbox, assetManager, source, output, formatType, ctx);
+    }
+
+    protected void addCommandContext(OP op, JSingleOperationContext opCtx, Map<String, Object> ctx) {}
 
     protected void operate(OP op, Toolbox toolbox, AssetManager assetManager, JAsset source, JAsset output, JFileExtension formatType, Map<String, Object> ctx) {
         if (source.hasList()) {

src/main/java/jvc/operation/exec/SplitExec.java

@@ -11,7 +11,6 @@ import org.cobbzilla.util.javascript.JsEngine;
 
 import java.io.File;
 import java.math.BigDecimal;
-import java.util.HashMap;
 import java.util.Map;
 
 import static org.cobbzilla.util.daemon.ZillaRuntime.die;
@@ -26,15 +25,13 @@ public class SplitExec extends ExecBase<SplitOperation> {
 
     @Override public void operate(SplitOperation op, Toolbox toolbox, AssetManager assetManager) {
 
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
+        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager, toolbox);
         final JAsset source = opCtx.source;
         final JAsset output = opCtx.output;
         final JFileExtension formatType = opCtx.formatType;
 
         final JsEngine js = toolbox.getJs();
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-        ctx.put("source", source);
+        final Map<String, Object> ctx = initialContext(toolbox, source);
 
         assetManager.addOperationArrayAsset(output);
         final BigDecimal incr = op.getIntervalIncr(ctx, js);

src/main/java/jvc/operation/exec/TrimExec.java

@@ -1,8 +1,6 @@
 package jvc.operation.exec;
 
 import jvc.model.JAsset;
-import jvc.model.JFileExtension;
-import jvc.model.operation.JSingleOperationContext;
 import jvc.operation.TrimOperation;
 import jvc.service.AssetManager;
 import jvc.service.Toolbox;
@@ -10,7 +8,6 @@ import lombok.extern.slf4j.Slf4j;
 import org.cobbzilla.util.javascript.StandardJsEngine;
 
 import java.math.BigDecimal;
-import java.util.HashMap;
 import java.util.Map;
 
 @Slf4j
@@ -24,19 +21,6 @@ public class TrimExec extends SingleOrMultiSourceExecBase<TrimOperation> {
 
     @Override protected String getProcessTemplate() { return TRIM_TEMPLATE; }
 
-    @Override public void operate(TrimOperation op, Toolbox toolbox, AssetManager assetManager) {
-
-        final JSingleOperationContext opCtx = op.getSingleInputContext(assetManager);
-        final JAsset source = opCtx.source;
-        final JAsset output = opCtx.output;
-        final JFileExtension formatType = opCtx.formatType;
-
-        final Map<String, Object> ctx = new HashMap<>();
-        ctx.put("ffmpeg", toolbox.getFfmpeg());
-
-        operate(op, toolbox, assetManager, source, output, formatType, ctx);
-    }
-
     @Override protected void process(Map<String, Object> ctx,
                                      TrimOperation op,
                                      JAsset source,

src/test/java/jvc/test/BasicTest.java

@@ -31,6 +31,7 @@ public class BasicTest {
     @Test public void testRemoveTrack () { runSpec("tests/test_remove_track.jvc"); }
     @Test public void testMergeAudio  () { runSpec("tests/test_merge_audio.jvc"); }
     @Test public void testAddSilence  () { runSpec("tests/test_add_silence.jvc"); }
+    @Test public void testAdjustSpeed () { runSpec("tests/test_adjust_speed.jvc"); }
 
     private void runSpec(String specPath) {
         try {

src/test/resources/tests/test_adjust_speed.jvc

@@ -0,0 +1,28 @@
+{
+  "assets": [
+    // this US government videos is covered by copyright
+    {
+      "name": "vid2",
+      "path": "https://archive.org/download/gov.archives.arc.49442/gov.archives.arc.49442_512kb.mp4",
+      "dest": "src/test/resources/sources/"
+    }
+  ],
+  "operations": [
+    // trim video first, so test runs faster
+    {
+      "operation": "trim",
+      "creates": "v2",
+      "source": "vid2",
+      "start": "10",
+      "end": "30"
+    },
+    {
+      "operation": "adjust-speed",     // name of the operation
+      "creates": "quickened",          // output asset name
+      "source": "v2",                  // main video asset
+      "factor": "4",                   // factor=1 is no change, factor>1 is faster, factor<1 is slower
+      "audio": "silent"                // audio: silent (default), unchanged, match
+                                       // if audio is match, then factor must be between 0.5 and 100
+    }
+  ]
+}