/*
- * AC3 parser
- * Copyright (c) 2003 Fabrice Bellard.
- * Copyright (c) 2003 Michael Niedermayer.
+ * AC-3 parser
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2003 Michael Niedermayer
*
- * 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
*/
+#include "libavutil/channel_layout.h"
#include "parser.h"
#include "ac3_parser.h"
#include "aac_ac3_parser.h"
-#include "bitstream.h"
+#include "get_bits.h"
#define AC3_HEADER_SIZE 7
1, 2, 3, 6
};
+/**
+ * Table for center mix levels
+ * reference: Section 5.4.2.4 cmixlev
+ */
+static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
+
+/**
+ * Table for surround mix levels
+ * reference: Section 5.4.2.5 surmixlev
+ */
+static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
+
-int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr)
+int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
- GetBitContext gbc;
+ int frame_size_code;
memset(hdr, 0, sizeof(*hdr));
- init_get_bits(&gbc, buf, 54);
-
- hdr->sync_word = get_bits(&gbc, 16);
+ hdr->sync_word = get_bits(gbc, 16);
if(hdr->sync_word != 0x0B77)
- return AC3_PARSE_ERROR_SYNC;
+ return AAC_AC3_PARSE_ERROR_SYNC;
- /* read ahead to bsid to make sure this is AC-3, not E-AC-3 */
- hdr->bsid = show_bits_long(&gbc, 29) & 0x1F;
- if(hdr->bsid > 10)
- return AC3_PARSE_ERROR_BSID;
+ /* read ahead to bsid to distinguish between AC-3 and E-AC-3 */
+ hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F;
+ if(hdr->bitstream_id > 16)
+ return AAC_AC3_PARSE_ERROR_BSID;
- hdr->crc1 = get_bits(&gbc, 16);
- hdr->fscod = get_bits(&gbc, 2);
- if(hdr->fscod == 3)
- return AC3_PARSE_ERROR_SAMPLE_RATE;
+ hdr->num_blocks = 6;
- hdr->frmsizecod = get_bits(&gbc, 6);
- if(hdr->frmsizecod > 37)
- return AC3_PARSE_ERROR_FRAME_SIZE;
+ /* set default mix levels */
+ hdr->center_mix_level = 5; // -4.5dB
+ hdr->surround_mix_level = 6; // -6.0dB
- skip_bits(&gbc, 5); // skip bsid, already got it
+ /* set default dolby surround mode */
+ hdr->dolby_surround_mode = AC3_DSURMOD_NOTINDICATED;
- hdr->bsmod = get_bits(&gbc, 3);
- hdr->acmod = get_bits(&gbc, 3);
- if((hdr->acmod & 1) && hdr->acmod != AC3_ACMOD_MONO) {
- hdr->cmixlev = get_bits(&gbc, 2);
- }
- if(hdr->acmod & 4) {
- hdr->surmixlev = get_bits(&gbc, 2);
- }
- if(hdr->acmod == AC3_ACMOD_STEREO) {
- hdr->dsurmod = get_bits(&gbc, 2);
- }
- hdr->lfeon = get_bits1(&gbc);
+ if(hdr->bitstream_id <= 10) {
+ /* Normal AC-3 */
+ hdr->crc1 = get_bits(gbc, 16);
+ hdr->sr_code = get_bits(gbc, 2);
+ if(hdr->sr_code == 3)
+ return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
+
+ frame_size_code = get_bits(gbc, 6);
+ if(frame_size_code > 37)
+ return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
- hdr->halfratecod = FFMAX(hdr->bsid, 8) - 8;
- hdr->sample_rate = ff_ac3_freqs[hdr->fscod] >> hdr->halfratecod;
- hdr->bit_rate = (ff_ac3_bitratetab[hdr->frmsizecod>>1] * 1000) >> hdr->halfratecod;
- hdr->channels = ff_ac3_channels[hdr->acmod] + hdr->lfeon;
- hdr->frame_size = ff_ac3_frame_sizes[hdr->frmsizecod][hdr->fscod] * 2;
+ skip_bits(gbc, 5); // skip bsid, already got it
+
+ hdr->bitstream_mode = get_bits(gbc, 3);
+ hdr->channel_mode = get_bits(gbc, 3);
+
+ if(hdr->channel_mode == AC3_CHMODE_STEREO) {
+ hdr->dolby_surround_mode = get_bits(gbc, 2);
+ } else {
+ if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
+ hdr-> center_mix_level = center_levels[get_bits(gbc, 2)];
+ if(hdr->channel_mode & 4)
+ hdr->surround_mix_level = surround_levels[get_bits(gbc, 2)];
+ }
+ hdr->lfe_on = get_bits1(gbc);
+
+ hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
+ hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
+ hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift;
+ hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
+ hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
+ hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
+ hdr->substreamid = 0;
+ } else {
+ /* Enhanced AC-3 */
+ hdr->crc1 = 0;
+ hdr->frame_type = get_bits(gbc, 2);
+ if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
+ return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
+
+ hdr->substreamid = get_bits(gbc, 3);
+
+ hdr->frame_size = (get_bits(gbc, 11) + 1) << 1;
+ if(hdr->frame_size < AC3_HEADER_SIZE)
+ return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
+
+ hdr->sr_code = get_bits(gbc, 2);
+ if (hdr->sr_code == 3) {
+ int sr_code2 = get_bits(gbc, 2);
+ if(sr_code2 == 3)
+ return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
+ hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
+ hdr->sr_shift = 1;
+ } else {
+ hdr->num_blocks = eac3_blocks[get_bits(gbc, 2)];
+ hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code];
+ hdr->sr_shift = 0;
+ }
+
+ hdr->channel_mode = get_bits(gbc, 3);
+ hdr->lfe_on = get_bits1(gbc);
+
+ hdr->bit_rate = (uint32_t)(8.0 * hdr->frame_size * hdr->sample_rate /
+ (hdr->num_blocks * 256.0));
+ hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
+ }
+ hdr->channel_layout = avpriv_ac3_channel_layout_tab[hdr->channel_mode];
+ if (hdr->lfe_on)
+ hdr->channel_layout |= AV_CH_LOW_FREQUENCY;
return 0;
}
-static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
- int *bit_rate, int *samples)
+static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
+ int *need_next_header, int *new_frame_start)
{
int err;
- unsigned int fscod, acmod, bsid, lfeon;
- unsigned int strmtyp, substreamid, frmsiz, fscod2, numblkscod;
- GetBitContext bits;
+ union {
+ uint64_t u64;
+ uint8_t u8[8 + AV_INPUT_BUFFER_PADDING_SIZE];
+ } tmp = { av_be2ne64(state) };
AC3HeaderInfo hdr;
+ GetBitContext gbc;
- err = ff_ac3_parse_header(buf, &hdr);
+ init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
+ err = avpriv_ac3_parse_header(&gbc, &hdr);
- if(err < 0 && err != -2)
+ if(err < 0)
return 0;
- bsid = hdr.bsid;
- if(bsid <= 10) { /* Normal AC-3 */
- *sample_rate = hdr.sample_rate;
- *bit_rate = hdr.bit_rate;
- *channels = hdr.channels;
- *samples = AC3_FRAME_SIZE;
- return hdr.frame_size;
- } else if (bsid > 10 && bsid <= 16) { /* Enhanced AC-3 */
- init_get_bits(&bits, &buf[2], (AC3_HEADER_SIZE-2) * 8);
- strmtyp = get_bits(&bits, 2);
- substreamid = get_bits(&bits, 3);
-
- if (strmtyp != 0 || substreamid != 0)
- return 0; /* Currently don't support additional streams */
-
- frmsiz = get_bits(&bits, 11) + 1;
- fscod = get_bits(&bits, 2);
- if (fscod == 3) {
- fscod2 = get_bits(&bits, 2);
- numblkscod = 3;
-
- if(fscod2 == 3)
- return 0;
-
- *sample_rate = ff_ac3_freqs[fscod2] / 2;
- } else {
- numblkscod = get_bits(&bits, 2);
-
- *sample_rate = ff_ac3_freqs[fscod];
- }
-
- acmod = get_bits(&bits, 3);
- lfeon = get_bits1(&bits);
-
- *samples = eac3_blocks[numblkscod] * 256;
- *bit_rate = frmsiz * (*sample_rate) * 16 / (*samples);
- *channels = ff_ac3_channels[acmod] + lfeon;
-
- return frmsiz * 2;
- }
-
- /* Unsupported bitstream version */
- return 0;
+ hdr_info->sample_rate = hdr.sample_rate;
+ hdr_info->bit_rate = hdr.bit_rate;
+ hdr_info->channels = hdr.channels;
+ hdr_info->channel_layout = hdr.channel_layout;
+ hdr_info->samples = hdr.num_blocks * 256;
+ hdr_info->service_type = hdr.bitstream_mode;
+ if (hdr.bitstream_mode == 0x7 && hdr.channels > 1)
+ hdr_info->service_type = AV_AUDIO_SERVICE_TYPE_KARAOKE;
+ if(hdr.bitstream_id>10)
+ hdr_info->codec_id = AV_CODEC_ID_EAC3;
+ else if (hdr_info->codec_id == AV_CODEC_ID_NONE)
+ hdr_info->codec_id = AV_CODEC_ID_AC3;
+
+ *need_next_header = (hdr.frame_type != EAC3_FRAME_TYPE_AC3_CONVERT);
+ *new_frame_start = (hdr.frame_type != EAC3_FRAME_TYPE_DEPENDENT);
+ return hdr.frame_size;
}
-static int ac3_parse_init(AVCodecParserContext *s1)
+static av_cold int ac3_parse_init(AVCodecParserContext *s1)
{
AACAC3ParseContext *s = s1->priv_data;
- s->inbuf_ptr = s->inbuf;
s->header_size = AC3_HEADER_SIZE;
s->sync = ac3_sync;
return 0;
}
-AVCodecParser ac3_parser = {
- { CODEC_ID_AC3 },
- sizeof(AACAC3ParseContext),
- ac3_parse_init,
- ff_aac_ac3_parse,
- NULL,
+AVCodecParser ff_ac3_parser = {
+ .codec_ids = { AV_CODEC_ID_AC3, AV_CODEC_ID_EAC3 },
+ .priv_data_size = sizeof(AACAC3ParseContext),
+ .parser_init = ac3_parse_init,
+ .parser_parse = ff_aac_ac3_parse,
+ .parser_close = ff_parse_close,
};
projects / ffmpeg / blobdiff