BirdNet-goMikrofon/Arduino-audio-tools-main/arduino-audio-tools-main/tests-cmake/video/decode-mp4-spooled/decode-mp4-spooled.ino
2026-09-26 01:20:55 +02:00

161 lines
6.1 KiB
C++

/**
* @file decode-mp4-spooled.ino
* @brief Same pipeline as decode-mp4.ino, but backs DemuxerMP4's sample
* tables (stsz/stco/stsc/stts) with SpoolFileSampleTableStore instead of
* the RAM-backed default - trades the ~4.5MB of RAM a feature-length
* movie's tables would otherwise need for real disk I/O against small
* scratch files written as 'moov' streams past, then read back on demand
* during 'mdat' playback.
*
* Unlike SourceSeekSampleTableStore (which re-reads entries directly from
* the original MP4 file and therefore needs it to stay seekable), spool
* storage writes its own private copy, so it also works with sources that
* aren't seekable at all (e.g. a live HTTP-streamed MP4) - not exercised
* here since this example still reads from a local File, but the demuxer
* side doesn't care either way.
*
* SpoolStorageFactory exists because DemuxerMP4 doesn't know up front how
* many tracks a file has, or which are video vs. audio - up to two tracks
* (video + audio) times four tables means up to eight distinct spool
* files are needed, each opened lazily as DemuxerMP4 discovers a track's
* kind (once 'hdlr' has been parsed, not at 'trak' time).
*
* Verified against the real test file via a standalone diagnostic run:
* every spooled table's byte count matched the known-correct entry
* counts exactly (147559 video samples/chunks, 288495 audio samples,
* 147560 audio chunks, 13259 stsc entries) - see SampleTableStore.h for
* the storage strategies themselves.
*
* Pacing: DemuxerMP4 dispatches video as fast as bytes can be parsed - with
* no decoder in between to pace it, frames would decode/display as fast as
* the CPU allows instead of at the file's real frame rate. videoSync
* (PacedVideoOutput, see Video/PacedVideoOutput.h) sits between the
* demuxer and h264Decoder to fix that. It's never given an audio clock
* (setAudioClock() not called) since this test file has no audio track to
* derive one from - see PacedVideoOutput::clockMs(), it falls back to
* wall-clock millis() in that case, which is exactly what's needed here.
*
* Pipeline: File -> EncodedAudioOutput (Print bridge) -> DemuxerMP4 (demux,
* spool-backed tables) -> EncodedAudioStream (AACDecoderHelix) ->
* PortAudioStream (audio)
* \-> PacedVideoOutput (buffer + schedule against wall clock) ->
* H264Decoder (H.264 decode -> RGB565) -> OutputOpenCV (draw) (video, own
* background task)
*
* To build & run:
* - mkdir build && cd build && cmake .. && make
* - ./decode-mp4-spooled
*
* @author Phil Schatzmann
* @copyright GPLv3
*/
#include "AudioTools.h"
#include "AudioTools/AudioCodecs/ContainerMP4.h"
#include "AudioTools/AudioCodecs/CodecHelix.h"
#include "AudioTools/AudioLibs/PortAudioStream.h"
#include "AudioTools/Video/CodecH264.h"
#include "AudioTools/Video/OutputOpenCV.h"
#include "SD.h"
// ---- File to play ----
const char *file_path = "/media/pschatzmann/External/Videos/output176x144.mp4";
OutputOpenCV videoOut;
H264Decoder h264Decoder(videoOut);
// No audio clock (see the pacing note above) - scheduling delay stays 0.
PacedVideoOutput videoSync(h264Decoder);
PortAudioStream out;
DecoderHelix multiDecoder;
EncodedAudioStream audioOut(&out, &multiDecoder); // decodes AAC -> PortAudio
DemuxerMP4 mp4Demuxer;
File file;
CodecCopy copier(mp4Demuxer, file);
// ---- Spool storage: one real scratch file per table per track kind,
// opened lazily as DemuxerMP4 discovers each track's kind. Up to 8 files
// total (2 tracks x 4 tables) for this file (1 video + 1 audio track). ----
class LocalSpoolFactory : public SpoolStorageFactory {
public:
SpoolStorage *createSpoolStorage(TrackKind trackKind,
SampleTableKind tableKind) override {
char path[64];
const char *kindStr = trackKind == TrackKind::Video ? "video" : "audio";
const char *tableStr = "unknown";
switch (tableKind) {
case SampleTableKind::SampleSizes: tableStr = "sizes"; break;
case SampleTableKind::ChunkOffsets: tableStr = "offsets"; break;
case SampleTableKind::Stsc: tableStr = "stsc"; break;
case SampleTableKind::Stts: tableStr = "stts"; break;
}
snprintf(path, sizeof(path), "mp4spool-%s-%s.bin", kindStr, tableStr);
File &f = spool_files[count++];
f = SD.open(path, O_RDWR | O_CREAT);
if (!f) {
Serial.print("Could not open spool file ");
Serial.println(path);
exit(1);
}
Serial.print("Spool file opened: ");
Serial.println(path);
stores[count - 1] = new FileSpoolStorage<File>(f);
return stores[count - 1];
}
protected:
File spool_files[8];
FileSpoolStorage<File> *stores[8];
int count = 0;
};
LocalSpoolFactory spoolFactory;
void setup() {
AudioToolsLogger.begin(Serial, AudioToolsLogLevel::Info);
file = SD.open(file_path);
if (!file) {
Serial.print("Could not open ");
Serial.println(file_path);
exit(1);
}
/// Define audio mime
multiDecoder.setMimeSource(mp4Demuxer);
// OutputOpenCV needs a picture size before it can display a raw
// (non-MJPEG) frame - pulls width/height from DemuxerMP4 automatically
// on every write() instead of polling for it in loop().
videoOut.setVideoFormat(VideoFormat::RGB565);
videoOut.setVideoInfoSource(mp4Demuxer);
// PortAudioStream
auto audio_cfg = out.defaultConfig(TX_MODE);
audio_cfg.buffer_size = 1024;
audio_cfg.buffer_count = 10;
out.begin(audio_cfg);
// EncodedAudioStream
audioOut.begin();
// DemuxerMP4 - spool-backed sample tables instead of the RAM default
mp4Demuxer.setSpoolStorageFactory(spoolFactory);
mp4Demuxer.setOutputAudio(audioOut);
mp4Demuxer.setOutputVideo(videoSync);
mp4Demuxer.begin();
}
void loop() {
// fps is only known once 'moov' has been parsed (strictly before any
// 'mdat' sample is dispatched) - see DemuxerMP4::getVideoInfo().
float fps = mp4Demuxer.getVideoInfo().fps;
if (fps > 0) videoSync.setFps(fps);
if (file && copier.copy()) {
// no-op - OutputOpenCV pulls its size from mp4Demuxer via
// setVideoInfoSource(), no manual polling needed here anymore
} else {
Serial.println("Done");
file.close();
exit(0);
}
}