1 files changed, 106 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/mpegaudio.h b/contrib/ffmpeg/libavcodec/mpegaudio.h
new file mode 100644
index 000000000..3eadf92a8
--- /dev/null
+++ b/contrib/ffmpeg/libavcodec/mpegaudio.h
@@ -0,0 +1,106 @@
+/*
+ * copyright (c) 2001 Fabrice Bellard
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file mpegaudio.h
+ * mpeg audio declarations for both encoder and decoder.
+ */
+
+/* max frame size, in samples */
+#define MPA_FRAME_SIZE 1152
+
+/* max compressed frame size */
+#define MPA_MAX_CODED_FRAME_SIZE 1792
+
+#define MPA_MAX_CHANNELS 2
+
+#define SBLIMIT 32 /* number of subbands */
+
+#define MPA_STEREO  0
+#define MPA_JSTEREO 1
+#define MPA_DUAL    2
+#define MPA_MONO    3
+
+/* header + layer + bitrate + freq + lsf/mpeg25 */
+#define SAME_HEADER_MASK \
+   (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
+
+/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
+   audio decoder */
+
+#ifdef USE_HIGHPRECISION
+#define FRAC_BITS   23   /* fractional bits for sb_samples and dct */
+#define WFRAC_BITS  16   /* fractional bits for window */
+#else
+#define FRAC_BITS   15   /* fractional bits for sb_samples and dct */
+#define WFRAC_BITS  14   /* fractional bits for window */
+#endif
+
+#if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)
+typedef int32_t OUT_INT;
+#define OUT_MAX INT32_MAX
+#define OUT_MIN INT32_MIN
+#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 31)
+#else
+typedef int16_t OUT_INT;
+#define OUT_MAX INT16_MAX
+#define OUT_MIN INT16_MIN
+#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
+#endif
+
+#if FRAC_BITS <= 15
+typedef int16_t MPA_INT;
+#else
+typedef int32_t MPA_INT;
+#endif
+
+int l2_select_table(int bitrate, int nb_channels, int freq, int lsf);
+int mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate);
+void ff_mpa_synth_init(MPA_INT *window);
+void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
+                         MPA_INT *window, int *dither_state,
+                         OUT_INT *samples, int incr,
+                         int32_t sb_samples[SBLIMIT]);
+
+extern const uint16_t mpa_bitrate_tab[2][3][15];
+extern const uint16_t mpa_freq_tab[3];
+extern const unsigned char *alloc_tables[5];
+extern const double enwindow[512];
+extern const int sblimit_table[5];
+extern const int quant_steps[17];
+extern const int quant_bits[17];
+extern const int32_t mpa_enwindow[257];
+
+/* fast header check for resync */
+static inline int ff_mpa_check_header(uint32_t header){
+    /* header */
+    if ((header & 0xffe00000) != 0xffe00000)
+        return -1;
+    /* layer check */
+    if ((header & (3<<17)) == 0)
+        return -1;
+    /* bit rate */
+    if ((header & (0xf<<12)) == 0xf<<12)
+        return -1;
+    /* frequency */
+    if ((header & (3<<10)) == 3<<10)
+        return -1;
+    return 0;
+}