cleaned up StreamActions interface
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This commit is contained in:
2026-07-27 23:00:37 +01:00
parent e19bc68006
commit df8afcb428
3 changed files with 215 additions and 130 deletions

View File

@@ -134,10 +134,9 @@ public class MediaService {
Job job = jobRegistryService.generateJob();
StreamActionsService.SegmentSelection ctx = resolveSegments(user, startTime, endTime);
float duration = (endTime.toEpochMilli() - startTime.toEpochMilli()) / 1000f;
Path outputFile = directoryService.getVodsDir(user.getId()).resolve(UUID.randomUUID() + ".mp4");
return dispatchSaveJob(job, ctx, duration, outputFile, () ->
return dispatchSaveJob(job, ctx, outputFile, () ->
vodService.persist(
title == null ? Instant.now().toString() : title,
description == null ? "" : description,
@@ -214,7 +213,7 @@ public class MediaService {
StreamActionsService.SegmentSelection ctx = resolveSegments(user, startTime, endTime);
Path outputFile = directoryService.getTempOutputDir().resolve(UUID.randomUUID() + ".mp4");
return dispatchSaveJob(job, ctx, duration, outputFile, () ->
return dispatchSaveJob(job, ctx, outputFile, () ->
clipService.persistClip(
title == null ? Instant.now().toString() : title,
description == null ? "" : description,
@@ -230,9 +229,9 @@ public class MediaService {
return streamActionsService.selectSegments(streamDir, startTime, endTime);
}
private Job dispatchSaveJob(Job job, StreamActionsService.SegmentSelection ctx, float duration, Path outputFile, Runnable onSuccess) {
private Job dispatchSaveJob(Job job, StreamActionsService.SegmentSelection ctx, Path outputFile, Runnable onSuccess) {
job.setState(JobState.PROCESSING);
streamActionsService.saveSection(ctx.segments(), ctx.trimOffset(), duration, outputFile, job.getProgressTracker())
streamActionsService.saveSection(ctx, outputFile, job.getProgressTracker())
.thenRun(() -> {
job.setDownload(outputFile);
job.setState(JobState.SUCCEEDED);

View File

@@ -16,17 +16,16 @@ import java.util.Comparator;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Service responsible for performing stream-related media actions, such as
* extracting and saving a trimmed section of video from a sequence of
* recorded segments.
* Extracts and saves a trimmed section of a stream from its recorded HLS
* segments.
* <p>
* Operations in this service are backed by {@code ffmpeg} and run
* asynchronously on a dedicated executor so that potentially long-running
* encoding/concatenation work does not block request-handling threads.
* The usual flow is {@link #selectSegments} to resolve the segments covering a
* time range into a {@link SegmentSelection}, then {@link #saveSection} to mux
* that selection to a file. Both are backed by {@code ffmpeg} and run on a
* dedicated executor so long-running encodes never block request threads.
*/
@Service
public class StreamActionsService {
@@ -40,66 +39,133 @@ public class StreamActionsService {
}
/**
* Concatenates a list of video segments and extracts a trimmed section
* from the result, writing the output to {@code outputFile}.
* <p>
* Failures (process launch errors, ffmpeg failures, interruption) are
* surfaced via the returned future rather than thrown, in line with
* normal {@link CompletableFuture} conventions — callers should use
* {@code .exceptionally()} / {@code .handle()} rather than a try/catch.
* A resolved section of a stream, ready to be muxed by {@link #saveSection}.
*
* @param segments the ordered list of segment files to concatenate,
* in playback order
* @param trimOffset the offset, in seconds, from the start of the
* concatenated stream at which to begin the trimmed
* section
* @param duration the duration, in seconds, of the trimmed section
* to extract
* @param outputFile the destination file the trimmed section will be
* written to; overwritten if it already exists
* @return a {@link CompletableFuture} that completes with the ffmpeg
* command output on success, or completes exceptionally on failure
* @param segments the segments to concatenate, in playback order; never empty
* @param trimOffset seconds to trim from the start of {@code segments.getFirst()}
* so playback begins at the requested moment, or {@code 0}
* when the first segment already starts there
* @param duration seconds of footage to keep, measured from the trim point.
* When the requested start fell in a recording gap and the
* leading segment was dropped, this is measured from the
* later real start so the section still ends where requested
*/
public record SegmentSelection(List<Path> segments, float trimOffset, float duration) {}
/**
* Resolves the recorded {@code .ts} segments covering {@code [startTime, endTime)}
* into a {@link SegmentSelection} ready for {@link #saveSection}.
* <p>
* The trim offset into the first segment is derived from {@code startTime}. If
* that start falls in a recording gap after the earliest overlapping segment
* (so the segment holds no footage for it), the segment is dropped and the
* selection instead begins at the next recorded footage.
*
* @param streamDirectory directory holding the stream's {@code .ts} segments
* @param startTime inclusive start of the requested section
* @param endTime exclusive end of the requested section; must be after {@code startTime}
* @return the segments, trim offset, and duration describing the section
* @throws IllegalArgumentException if {@code startTime} is not before {@code endTime},
* or no segment holds footage for the range
* @throws IOException if listing the directory or probing a segment fails
*/
public SegmentSelection selectSegments(Path streamDirectory, Instant startTime, Instant endTime) throws IOException {
List<Path> segments = findOverlappingSegments(streamDirectory, startTime, endTime);
if (segments.isEmpty()) {
throw new IllegalArgumentException("No stream segments found in the given time range");
}
long firstMs = parseTimestampMs(segments.getFirst());
float trimOffset = Math.max(0f, (startTime.toEpochMilli() - firstMs) / 1000f);
// A first segment shorter than the trim offset means the requested start
// lands in a gap after it; drop it and begin at the next recorded footage.
if (trimOffset > 0 && probeDurationSeconds(segments.getFirst()) < trimOffset) {
segments.removeFirst();
if (segments.isEmpty()) {
throw new IllegalArgumentException("No recorded footage at the requested start time");
}
firstMs = parseTimestampMs(segments.getFirst());
trimOffset = 0f;
}
// Measure duration from where playback actually begins so a dropped
// leading segment shortens the section rather than overrunning endTime.
long effectiveStartMs = firstMs + (long) (trimOffset * 1000);
float duration = (endTime.toEpochMilli() - effectiveStartMs) / 1000f;
return new SegmentSelection(segments, trimOffset, duration);
}
/**
* Muxes a {@link SegmentSelection} to {@code outputFile}, trimming the leading
* segment to {@code selection.trimOffset()} and keeping {@code selection.duration()}
* seconds of footage.
* <p>
* Runs asynchronously; failures (process-launch errors, ffmpeg failures,
* interruption) complete the returned future exceptionally rather than being
* thrown, so callers should use {@link CompletableFuture#exceptionally} or
* {@link CompletableFuture#handle} rather than try/catch.
*
* @param selection the segments, trim offset, and duration to write
* (see {@link #selectSegments})
* @param outputFile destination for the muxed section; overwritten if present
* @param progressTracker receives progress updates as ffmpeg runs
* @return a future completing with the ffmpeg output, or exceptionally on failure
*/
@Async("ffmpegTaskExecutor")
public CompletableFuture<CommandOutput> saveSection(
List<Path> segments,
float trimOffset,
float duration,
SegmentSelection selection,
Path outputFile,
ProgressTracker progressTracker
) {
List<Path> segments = selection.segments();
float trimOffset = selection.trimOffset();
float duration = selection.duration();
if (segments.isEmpty()) {
return CompletableFuture.failedFuture(new IllegalArgumentException("Segment list cannot be empty"));
return CompletableFuture.failedFuture(new IllegalArgumentException("Selection must contain at least one segment"));
}
if (trimOffset < 0 || duration <= 0) {
return CompletableFuture.failedFuture(new IllegalArgumentException(
"trimOffset must be >= 0 and duration must be > 0 (got " + trimOffset + ", " + duration + ")"));
}
Path headSegment = null;
Path headFragment = null;
Path concatList = null;
try {
// Unique per invocation so concurrent saves by different users never
// collide on the same head fragment; cleaned up in the finally block.
headSegment = Files.createTempFile("reencode-section-", ".ts");
encodeHead(segments.getFirst(), trimOffset, headSegment);
// Only the first segment is trimmed, so re-encode just that fragment and
// stream-copy the rest. A zero offset means the first segment already
// starts at the requested point, so re-encoding it would be wasted work.
List<Path> fragments;
if (trimOffset > 0) {
headFragment = Files.createTempFile("reencode-section-", ".ts");
encodeHead(segments.getFirst(), trimOffset, headFragment);
String concatInput = Stream.concat(Stream.of(headSegment), segments.stream().skip(1))
.map(p -> p.toAbsolutePath().toString())
.collect(Collectors.joining("|"));
fragments = new ArrayList<>();
fragments.add(headFragment);
fragments.addAll(segments.subList(1, segments.size()));
} else {
fragments = segments;
}
// The concat demuxer (unlike the concat: byte protocol) rebases each
// fragment's timestamps to run continuously across the joins, absorbing
// the discontinuity between the PTS-0 head and the copied fragments.
concatList = writeConcatList(fragments);
List<String> command = List.of(
"ffmpeg",
"-y",
"-i", "concat:" + concatInput,
"-f", "concat",
"-safe", "0",
"-i", concatList.toAbsolutePath().toString(),
"-t", String.valueOf(duration),
"-c", "copy",
outputFile.toAbsolutePath().toString()
);
logger.info("Saving section with ({} segments) to '{}'",
segments.size(), outputFile);
logger.info("Saving section ({} segments) to '{}'", segments.size(), outputFile);
CommandOutput output = commandRunner.run(command, line -> commandRunner.setProgress(line, progressTracker, duration));
progressTracker.markComplete();
@@ -115,25 +181,47 @@ public class StreamActionsService {
logger.error("Failed to save section to '{}': {}", outputFile, e.toString());
return CompletableFuture.failedFuture(e);
} finally {
if (headSegment != null) {
try {
Files.deleteIfExists(headSegment);
} catch (IOException e) {
logger.warn("Failed to delete temp head fragment '{}': {}", headSegment, e.toString());
}
}
deleteTempQuietly(headFragment);
deleteTempQuietly(concatList);
}
}
private List<Path> getSegmentsInRange(Path streamDirectory, Instant startTime, Instant endTime) throws IOException {
/**
* Parses the start timestamp encoded in an HLS segment's filename (e.g.
* {@code 1712345678.ts}). nginx names fragments in whole seconds, so
* second-scale values are scaled up to milliseconds.
*
* @param path a {@code .ts} segment path
* @return the segment's start time in epoch milliseconds
* @throws IllegalArgumentException if {@code path} is not a {@code .ts} file
* @throws NumberFormatException if the filename stem is not numeric
*/
public long parseTimestampMs(Path path) {
String fullName = path.getFileName().toString();
if (!fullName.endsWith(".ts")) {
throw new IllegalArgumentException("File must end in ts");
}
String name = fullName.substring(0, fullName.length() - 3);
long value = Long.parseLong(name);
return value < 1_000_000_000_000L ? value * 1000L : value;
}
/**
* Lists the {@code .ts} segments whose playback interval overlaps
* {@code [startTime, endTime)}, in playback order. A segment spans from its
* own timestamp up to the next segment's timestamp (or open-ended for the last).
*/
private List<Path> findOverlappingSegments(Path streamDirectory, Instant startTime, Instant endTime) throws IOException {
long startMs = startTime.toEpochMilli();
long endMs = endTime.toEpochMilli();
if (endTime.toEpochMilli() <= startTime.toEpochMilli()) {
if (endMs <= startMs) {
throw new IllegalArgumentException("Start time must be before end time");
}
List<Path> results = new ArrayList<>();
List<Path> overlapping = new ArrayList<>();
try (Stream<Path> files = Files.list(streamDirectory)) {
List<Path> streamFiles = files
@@ -151,54 +239,12 @@ public class StreamActionsService {
: Long.MAX_VALUE;
if (segmentStart < endMs && segmentEnd > startMs) {
results.add(streamFile);
overlapping.add(streamFile);
}
}
}
return results;
}
/**
* The segments backing a save and the offset into the first one at which
* the requested section begins.
*
* @param segments the ordered segments to concatenate, in playback order
* @param trimOffset the offset, in seconds, into {@code segments.getFirst()}
* at which the requested section starts
*/
public record SegmentSelection(List<Path> segments, float trimOffset) {}
/**
* Selects the recorded {@code .ts} segments overlapping {@code [startTime, endTime)}
* and computes the trim offset into the first segment.
* <p>
* If {@code startTime} falls in a stream gap after the earliest overlapping segment
* (so that segment holds no footage for the requested start), the segment is dropped
* and the selection begins at the first genuinely-recorded footage instead.
*
* @throws IllegalArgumentException if no segments hold footage for the requested range
* @throws IOException if listing the stream directory or probing a segment fails
*/
public SegmentSelection selectSegments(Path streamDirectory, Instant startTime, Instant endTime) throws IOException {
List<Path> segments = getSegmentsInRange(streamDirectory, startTime, endTime);
if (segments.isEmpty()) {
throw new IllegalArgumentException("No stream segments found in the given time range");
}
long firstMs = parseTimestampMs(segments.getFirst());
float trimOffset = Math.max(0f, (startTime.toEpochMilli() - firstMs) / 1000f);
// if the first segment is longer than the trim-offset
if (trimOffset > 0 && probeDurationSeconds(segments.getFirst()) < trimOffset) {
segments.removeFirst();
if (segments.isEmpty()) {
throw new IllegalArgumentException("No recorded footage at the requested start time");
}
trimOffset = 0f;
}
return new SegmentSelection(segments, trimOffset);
return overlapping;
}
private float probeDurationSeconds(Path segment) throws IOException {
@@ -212,24 +258,6 @@ public class StreamActionsService {
}
}
public long parseTimestampMs(Path path) {
String fullName = path.getFileName().toString();
if (!fullName.endsWith(".ts")) {
throw new IllegalArgumentException("File must end in ts");
}
String name = fullName.substring(0, fullName.length() - 3);
long value = Long.parseLong(name);
// nginx hls_fragment_naming system uses seconds; convert to ms
return value < 1_000_000_000_000L ? value * 1000L : value;
}
/**
* Re-encodes {@code firstSegment} from {@code trimOffset} to its end,
* writing an MPEG-TS fragment that can be stream-copy concatenated with
* the untouched fragments that follow it.
*/
private void encodeHead(Path firstSegment, float trimOffset, Path head)
throws IOException, InterruptedException {
@@ -251,11 +279,30 @@ public class StreamActionsService {
);
logger.debug("Re-encoding head fragment '{}' from {}s", firstSegment, trimOffset);
commandRunner.run(command, line -> { /* head pass is short; not worth reporting */ });
commandRunner.run(command, line -> { /* head pass is short; no progress reporting */ });
if (!Files.exists(head) || Files.size(head) == 0) {
throw new IOException("Head re-encode produced no output — trimOffset " + trimOffset
+ "s may exceed the duration of " + firstSegment);
}
}
private Path writeConcatList(List<Path> fragments) throws IOException {
Path listFile = Files.createTempFile("concat-list-", ".txt");
List<String> lines = fragments.stream()
.map(p -> "file '" + p.toAbsolutePath().toString().replace("'", "'\\''") + "'")
.toList();
Files.write(listFile, lines);
return listFile;
}
private void deleteTempQuietly(Path tempFile) {
if (tempFile != null) {
try {
Files.deleteIfExists(tempFile);
} catch (IOException e) {
logger.warn("Failed to delete temp file '{}': {}", tempFile, e.toString());
}
}
}
}

View File

@@ -247,6 +247,8 @@ class StreamActionsServiceTest {
assertThat(selection.segments()).extracting(p -> p.getFileName().toString())
.containsExactly("30.ts", "33.ts");
assertThat(selection.trimOffset()).isEqualTo(1.5f);
// effective start equals the requested 31.5s, so duration runs to endTime: 40 - 31.5
assertThat(selection.duration()).isEqualTo(8.5f);
}
@Test
@@ -262,6 +264,10 @@ class StreamActionsServiceTest {
assertThat(selection.segments()).extracting(p -> p.getFileName().toString())
.containsExactly("100.ts", "110.ts");
assertThat(selection.trimOffset()).isZero();
// the dropped head shifts the effective start to 100s, so the duration
// shrinks to end at endTime (111 - 100 = 11s) instead of the 41s the
// original 70s->111s window would have implied
assertThat(selection.duration()).isEqualTo(11f);
}
@Test
@@ -351,13 +357,15 @@ class StreamActionsServiceTest {
stubRunnerProducingHead(commandOutput);
var future = service.saveSection(List.of(segmentA, segmentB), 5.0f, 12.0f, output, progress);
var future = service.saveSection(
new StreamActionsService.SegmentSelection(List.of(segmentA, segmentB), 5.0f, 12.0f), output, progress);
assertThat(future.get()).isSameAs(commandOutput);
assertThat(progress.isComplete()).isTrue();
// saveSection issues two ffmpeg passes: the head re-encode (trims the
// first segment via -ss) followed by the stream-copy concat (-t/-c copy).
// With a non-zero trim offset saveSection issues two ffmpeg passes: the
// head re-encode (trims the first segment via -ss) followed by the
// concat-demuxer stream copy (-f concat / -t / -c copy).
@SuppressWarnings("unchecked")
ArgumentCaptor<List<String>> captor = ArgumentCaptor.forClass(List.class);
Mockito.verify(commandRunner, Mockito.times(2)).run(captor.capture(), any());
@@ -365,20 +373,50 @@ class StreamActionsServiceTest {
List<String> concatCommand = captor.getAllValues().get(1);
assertThat(headCommand).containsSequence("-ss", "5.0");
assertThat(concatCommand).containsSequence("-f", "concat");
assertThat(concatCommand).containsSequence("-t", "12.0");
assertThat(concatCommand).containsSequence("-c", "copy");
assertThat(concatCommand).endsWith(output.toAbsolutePath().toString());
}
@Test
void saveSection_zeroTrimOffset_skipsHeadReencodeAndRunsSingleConcatPass() throws Exception {
Path output = Path.of("/tmp/out/clip.mp4");
ProgressTracker progress = new ProgressTracker();
CommandOutput commandOutput = new CommandOutput();
when(commandRunner.run(anyList(), any())).thenReturn(commandOutput);
var future = service.saveSection(
new StreamActionsService.SegmentSelection(
List.of(Path.of("/tmp/a.ts"), Path.of("/tmp/b.ts")), 0f, 10f), output, progress);
assertThat(future.get()).isSameAs(commandOutput);
assertThat(progress.isComplete()).isTrue();
// trimOffset 0 means the first segment already starts at the requested point:
// no head re-encode pass, just a single concat-demuxer copy (no -ss).
@SuppressWarnings("unchecked")
ArgumentCaptor<List<String>> captor = ArgumentCaptor.forClass(List.class);
Mockito.verify(commandRunner, Mockito.times(1)).run(captor.capture(), any());
List<String> command = captor.getValue();
assertThat(command).containsSequence("-f", "concat");
assertThat(command).containsSequence("-t", "10.0");
assertThat(command).doesNotContain("-ss");
}
@Test
void saveSection_commandRunnerThrowsIOException_completesExceptionallyWithoutMarkingProgressComplete() throws Exception {
Path output = Path.of("/tmp/out/clip.mp4");
ProgressTracker progress = new ProgressTracker();
// The head re-encode is the first ffmpeg pass; its failure must surface.
// With a non-zero trim offset the head re-encode is the first ffmpeg pass;
// its failure must surface.
when(commandRunner.run(anyList(), any())).thenThrow(new IOException("ffmpeg boom"));
var future = service.saveSection(List.of(Path.of("/tmp/a.ts")), 0f, 10f, output, progress);
var future = service.saveSection(
new StreamActionsService.SegmentSelection(List.of(Path.of("/tmp/a.ts")), 2f, 10f), output, progress);
assertThatThrownBy(future::get)
.isInstanceOf(ExecutionException.class)
@@ -391,7 +429,8 @@ class StreamActionsServiceTest {
Path output = Path.of("/tmp/out/clip.mp4");
ProgressTracker progress = new ProgressTracker();
var future = service.saveSection(List.of(), 0f, 10f, output, progress);
var future = service.saveSection(
new StreamActionsService.SegmentSelection(List.of(), 0f, 10f), output, progress);
assertThatThrownBy(future::get)
.isInstanceOf(ExecutionException.class)
@@ -400,13 +439,13 @@ class StreamActionsServiceTest {
}
@Test
void saveSection_nullOutputFile_completesExceptionally() throws Exception {
void saveSection_nullOutputFile_completesExceptionally() {
ProgressTracker progress = new ProgressTracker();
// Let the head pass succeed so execution reaches the null output file.
stubRunnerProducingHead(new CommandOutput());
var future = service.saveSection(List.of(Path.of("/tmp/a.ts")), 0f, 10f, null, progress);
// trimOffset 0 skips the head pass; building the concat command dereferences
// the null output path, so no ffmpeg pass ever runs.
var future = service.saveSection(
new StreamActionsService.SegmentSelection(List.of(Path.of("/tmp/a.ts")), 0f, 10f), null, progress);
assertThatThrownBy(future::get)
.isInstanceOf(ExecutionException.class)