1 files changed, 125 insertions, 0 deletions
diff --git a/TOOLS/302m_convert.c b/TOOLS/302m_convert.c
new file mode 100644
index 0000000000..14c0af4b29
--- /dev/null
+++ b/TOOLS/302m_convert.c
@@ -0,0 +1,125 @@
+/**
+ * convert D-Cinema Audio (probably SMPTE 302M) to a
+ * wav file that MPlayer can play.
+ * Usage: 302m_convert <infile> <outfile>
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <byteswap.h>
+#define le2me_32(x) (x)
+#define le2me_16(x) (x)
+#define be2me_16(x) bswap_16(x)
+
+// From MPlayer libao/ao_pcm.c
+#define WAV_ID_RIFF 0x46464952 /* "RIFF" */
+#define WAV_ID_WAVE 0x45564157 /* "WAVE" */
+#define WAV_ID_FMT  0x20746d66 /* "fmt " */
+#define WAV_ID_DATA 0x61746164 /* "data" */
+#define WAV_ID_PCM  0x0001
+
+struct WaveHeader {
+  uint32_t riff;
+  uint32_t file_length;
+  uint32_t wave;
+  uint32_t fmt;
+  uint32_t fmt_length;
+  uint16_t fmt_tag;
+  uint16_t channels;
+  uint32_t sample_rate;
+  uint32_t bytes_per_second;
+  uint16_t block_align;
+  uint16_t bits;
+  uint32_t data;
+  uint32_t data_length;
+};
+
+static struct WaveHeader wavhdr = {
+  le2me_32(WAV_ID_RIFF),
+  le2me_32(0x7fffffff),
+  le2me_32(WAV_ID_WAVE),
+  le2me_32(WAV_ID_FMT),
+  le2me_32(16),
+  le2me_16(WAV_ID_PCM),
+  le2me_16(6),
+  le2me_32(96000),
+  le2me_32(1728000),
+  le2me_16(18),
+  le2me_16(24),
+  le2me_32(WAV_ID_DATA),
+  le2me_32(0x7fffffff),
+};
+
+// this format is completely braindead, and this bitorder
+// is the result of pure guesswork (counting how often
+// the bits flip), so it might be wrong.
+void fixup(unsigned char *in_, unsigned char *out) {
+  int i;
+  unsigned char in[3] = {in_[0], in_[1], in_[2]};
+  unsigned char sync = in[2] & 0x0f; // sync flags
+  in[2] >>= 4;
+  out[2] = 0;
+  for (i = 0; i < 4; i++) {
+    out[2] <<= 1;
+    out[2] |= in[2] & 1;
+    in[2] >>= 1;
+  }
+  for (i = 0; i < 4; i++) {
+    out[2] <<= 1;
+    out[2] |= in[1] & 1;
+    in[1] >>= 1;
+  }
+  out[1] = 0;
+  for (i = 0; i < 4; i++) {
+    out[1] <<= 1;
+    out[1] |= in[1] & 1;
+    in[1] >>= 1;
+  }
+  for (i = 0; i < 4; i++) {
+    out[1] <<= 1;
+    out[1] |= in[0] & 1;
+    in[0] >>= 1;
+  }
+  out[0] = 0;
+  for (i = 0; i < 4; i++) {
+    out[0] <<= 1;
+    out[0] |= in[0] & 1;
+    in[0] >>= 1;
+  }
+  out[0] <<= 4;
+  out[0] |= sync; // sync flags go into lowest bits
+  // it seems those might also contain audio data,
+  // don't know if this is the right order then
+  // these might be also useful to detect the number
+  // of channels in case there are files with != 6 channels
+}
+
+int main(int argc, char *argv[]) {
+  FILE *in = fopen(argv[1], "r");
+  FILE *out = fopen(argv[2], "w");
+  int i;
+  uint16_t blocklen, unknown;
+  unsigned char *block;
+  if (!in) {
+    printf("Could not open %s for reading\n", argv[1]);
+    return EXIT_FAILURE;
+  }
+  if (!out) {
+    printf("Could not open %s for writing\n", argv[2]);
+    return EXIT_FAILURE;
+  }
+  fwrite(&wavhdr, 1, sizeof(wavhdr), out);
+  do {
+    fread(&blocklen, 2, 1, in);
+    blocklen = be2me_16(blocklen);
+    fread(&unknown, 2, 1, in);
+    block = malloc(blocklen);
+    blocklen = fread(block, 1, blocklen, in);
+    for (i = 0; i < blocklen; i += 3)
+      fixup(&block[i], &block[i]);
+    fwrite(block, 1, blocklen, out);
+    free(block);
+  } while (!feof(in));
+  return EXIT_SUCCESS;
+}
+