+/*
+ * 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
+#define MPA_FRAME_SIZE 1152
/* max compressed frame size */
#define MPA_MAX_CODED_FRAME_SIZE 1792
#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 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;
+}