/*
* MPEG Audio header decoder
- * Copyright (c) 2001, 2002 Fabrice Bellard.
+ * Copyright (c) 2001, 2002 Fabrice Bellard
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file mpegaudiodecheader.c
+ * @file
* MPEG Audio header decoder.
*/
-//#define DEBUG
#include "avcodec.h"
#include "mpegaudio.h"
#include "mpegaudiodata.h"
+#include "mpegaudiodecheader.h"
-int decode_header(MPADecodeContext *s, uint32_t header)
+int avpriv_mpegaudio_decode_header(MPADecodeHeader *s, uint32_t header)
{
int sample_rate, frame_size, mpeg25, padding;
int sample_rate_index, bitrate_index;
s->layer = 4 - ((header >> 17) & 3);
/* extract frequency */
sample_rate_index = (header >> 10) & 3;
- sample_rate = ff_mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
+ sample_rate = avpriv_mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
sample_rate_index += 3 * (s->lsf + mpeg25);
s->sample_rate_index = sample_rate_index;
s->error_protection = ((header >> 16) & 1) ^ 1;
s->nb_channels = 2;
if (bitrate_index != 0) {
- frame_size = ff_mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
+ frame_size = avpriv_mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
s->bit_rate = frame_size * 1000;
switch(s->layer) {
case 1:
}
#if defined(DEBUG)
- dprintf(s->avctx, "layer%d, %d Hz, %d kbits/s, ",
+ av_dlog(NULL, "layer%d, %d Hz, %d kbits/s, ",
s->layer, s->sample_rate, s->bit_rate);
if (s->nb_channels == 2) {
if (s->layer == 3) {
if (s->mode_ext & MODE_EXT_MS_STEREO)
- dprintf(s->avctx, "ms-");
+ av_dlog(NULL, "ms-");
if (s->mode_ext & MODE_EXT_I_STEREO)
- dprintf(s->avctx, "i-");
+ av_dlog(NULL, "i-");
}
- dprintf(s->avctx, "stereo");
+ av_dlog(NULL, "stereo");
} else {
- dprintf(s->avctx, "mono");
+ av_dlog(NULL, "mono");
}
- dprintf(s->avctx, "\n");
+ av_dlog(NULL, "\n");
#endif
return 0;
}
+
+int avpriv_mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate, int *channels, int *frame_size, int *bit_rate)
+{
+ MPADecodeHeader s1, *s = &s1;
+
+ if (ff_mpa_check_header(head) != 0)
+ return -1;
+
+ if (avpriv_mpegaudio_decode_header(s, head) != 0) {
+ return -1;
+ }
+
+ switch(s->layer) {
+ case 1:
+ avctx->codec_id = AV_CODEC_ID_MP1;
+ *frame_size = 384;
+ break;
+ case 2:
+ avctx->codec_id = AV_CODEC_ID_MP2;
+ *frame_size = 1152;
+ break;
+ default:
+ case 3:
+ avctx->codec_id = AV_CODEC_ID_MP3;
+ if (s->lsf)
+ *frame_size = 576;
+ else
+ *frame_size = 1152;
+ break;
+ }
+
+ *sample_rate = s->sample_rate;
+ *channels = s->nb_channels;
+ *bit_rate = s->bit_rate;
+ return s->frame_size;
+}