fix(android): consolidate native media decoders

android/app/src/test/cpp/ffmpeg_audio_buffer_test.cpp

@@ -0,0 +1,76 @@
+#include "../../main/cpp/media3_ffmpeg_decoder/ffmpeg_audio_buffer.h"
+
+#include <climits>
+#include <cstdio>
+
+namespace {
+
+bool check(bool condition, const char* message) {
+  if (!condition) std::fprintf(stderr, "%s\n", message);
+  return condition;
+}
+
+bool computesPackedPcmSizes() {
+  int bytes = -1;
+  return check(plezy::ffmpeg::CheckedAudioByteCount(1024, 2, 2, &bytes), "stereo PCM size rejected") &&
+         check(bytes == 4096, "wrong stereo PCM size") &&
+         check(plezy::ffmpeg::CheckedAudioByteCount(1024, 6, 4, &bytes), "5.1 float PCM size rejected") &&
+         check(bytes == 24576, "wrong 5.1 float PCM size") &&
+         check(plezy::ffmpeg::CheckedAudioByteCount(1024, 8, 2, &bytes), "7.1 PCM size rejected") &&
+         check(bytes == 16384, "wrong 7.1 PCM size");
+}
+
+bool usesConvertedSampleCount() {
+  int capacity = -1;
+  int written = -1;
+  return check(plezy::ffmpeg::CheckedAudioByteCount(2048, 6, 2, &capacity), "output capacity rejected") &&
+         check(plezy::ffmpeg::CheckedAudioByteCount(1536, 6, 2, &written), "converted sample count rejected") &&
+         check(capacity == 24576, "wrong output capacity") && check(written == 18432, "wrong converted byte count") &&
+         check(written < capacity, "converted bytes must not equal an unused upper bound");
+}
+
+bool rejectsInvalidAndOverflowingSizes() {
+  int bytes = 7;
+  const int largestSafeStereoSampleCount = INT_MAX / 4;
+  return check(!plezy::ffmpeg::CheckedAudioByteCount(-1, 2, 2, &bytes), "negative samples accepted") &&
+         check(!plezy::ffmpeg::CheckedAudioByteCount(1, 0, 2, &bytes), "zero channels accepted") &&
+         check(!plezy::ffmpeg::CheckedAudioByteCount(1, 2, 0, &bytes), "zero sample size accepted") &&
+         check(
+             !plezy::ffmpeg::CheckedAudioByteCount(largestSafeStereoSampleCount + 1, 2, 2, &bytes),
+             "multiplication overflow accepted") &&
+         check(!plezy::ffmpeg::CheckedAddByteCount(INT_MAX, 1, &bytes), "addition overflow accepted") &&
+         check(!plezy::ffmpeg::CheckedAddByteCount(-1, 1, &bytes), "negative accumulated size accepted");
+}
+
+bool acceptsEmptyOutputAndIntBoundary() {
+  int bytes = -1;
+  int total = -1;
+  return check(plezy::ffmpeg::CheckedAudioByteCount(0, 8, 4, &bytes), "empty output rejected") &&
+         check(bytes == 0, "empty output is not zero bytes") &&
+         check(plezy::ffmpeg::CheckedAddByteCount(INT_MAX - 4, 4, &total), "INT_MAX boundary rejected") &&
+         check(total == INT_MAX, "wrong INT_MAX boundary sum");
+}
+
+}  // namespace
+
+int main() {
+  struct TestCase {
+    const char* name;
+    bool (*run)();
+  };
+  const TestCase tests[] = {
+      {"packed PCM sizes", computesPackedPcmSizes},
+      {"converted sample count", usesConvertedSampleCount},
+      {"invalid and overflowing sizes", rejectsInvalidAndOverflowingSizes},
+      {"empty output and boundary", acceptsEmptyOutputAndIntBoundary},
+  };
+
+  for (const TestCase& test : tests) {
+    if (!test.run()) {
+      std::fprintf(stderr, "FAILED: %s\n", test.name);
+      return 1;
+    }
+  }
+  std::printf("Passed %zu ffmpeg_audio_buffer tests\n", sizeof(tests) / sizeof(tests[0]));
+  return 0;
+}