/*
- * 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.
*
#include "parser.h"
#include "ac3_parser.h"
#include "aac_ac3_parser.h"
-#include "bitstream.h"
+#include "get_bits.h"
#define AC3_HEADER_SIZE 7
};
-int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr)
+int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
- GetBitContext gbc;
int frame_size_code;
- int num_blocks;
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 distinguish between AC-3 and E-AC-3 */
- hdr->bitstream_id = show_bits_long(&gbc, 29) & 0x1F;
+ hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F;
if(hdr->bitstream_id > 16)
- return AC3_PARSE_ERROR_BSID;
+ return AAC_AC3_PARSE_ERROR_BSID;
+
+ hdr->num_blocks = 6;
+
+ /* set default mix levels */
+ hdr->center_mix_level = 1; // -4.5dB
+ hdr->surround_mix_level = 1; // -6.0dB
if(hdr->bitstream_id <= 10) {
/* Normal AC-3 */
- hdr->crc1 = get_bits(&gbc, 16);
- hdr->sr_code = get_bits(&gbc, 2);
+ hdr->crc1 = get_bits(gbc, 16);
+ hdr->sr_code = get_bits(gbc, 2);
if(hdr->sr_code == 3)
- return AC3_PARSE_ERROR_SAMPLE_RATE;
+ return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
- frame_size_code = get_bits(&gbc, 6);
+ frame_size_code = get_bits(gbc, 6);
if(frame_size_code > 37)
- return AC3_PARSE_ERROR_FRAME_SIZE;
+ return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
- skip_bits(&gbc, 5); // skip bsid, already got it
+ skip_bits(gbc, 5); // skip bsid, already got it
+
+ skip_bits(gbc, 3); // skip bitstream mode
+ hdr->channel_mode = get_bits(gbc, 3);
- skip_bits(&gbc, 3); // skip bitstream mode
- hdr->channel_mode = get_bits(&gbc, 3);
- if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO) {
- skip_bits(&gbc, 2); // skip center mix level
- }
- if(hdr->channel_mode & 4) {
- skip_bits(&gbc, 2); // skip surround mix level
- }
if(hdr->channel_mode == AC3_CHMODE_STEREO) {
- skip_bits(&gbc, 2); // skip dolby surround mode
+ skip_bits(gbc, 2); // skip dsurmod
+ } else {
+ if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
+ hdr->center_mix_level = get_bits(gbc, 2);
+ if(hdr->channel_mode & 4)
+ hdr->surround_mix_level = get_bits(gbc, 2);
}
- hdr->lfe_on = get_bits1(&gbc);
+ 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_INDEPENDENT;
+ 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);
+ hdr->frame_type = get_bits(gbc, 2);
if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
- return AC3_PARSE_ERROR_FRAME_TYPE;
+ return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
- skip_bits(&gbc, 3); // skip substream id
+ hdr->substreamid = get_bits(gbc, 3);
- hdr->frame_size = (get_bits(&gbc, 11) + 1) << 1;
+ hdr->frame_size = (get_bits(gbc, 11) + 1) << 1;
if(hdr->frame_size < AC3_HEADER_SIZE)
- return AC3_PARSE_ERROR_FRAME_SIZE;
+ return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
- hdr->sr_code = get_bits(&gbc, 2);
+ hdr->sr_code = get_bits(gbc, 2);
if (hdr->sr_code == 3) {
- int sr_code2 = get_bits(&gbc, 2);
+ int sr_code2 = get_bits(gbc, 2);
if(sr_code2 == 3)
- return AC3_PARSE_ERROR_SAMPLE_RATE;
+ return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
hdr->sr_shift = 1;
- num_blocks = 6;
} else {
- num_blocks = eac3_blocks[get_bits(&gbc, 2)];
+ 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->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 /
- (num_blocks * 256.0));
+ (hdr->num_blocks * 256.0));
hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
}
+ hdr->channel_layout = ff_ac3_channel_layout_tab[hdr->channel_mode];
+ if (hdr->lfe_on)
+ hdr->channel_layout |= CH_LOW_FREQUENCY;
return 0;
}
-static int ac3_sync(AACAC3ParseContext *hdr_info, AACAC3FrameFlag *flag)
+int ff_ac3_parse_header_full(GetBitContext *gbc, AC3HeaderInfo *hdr){
+ int ret, i;
+ ret = ff_ac3_parse_header(gbc, hdr);
+ if(!ret){
+ if(hdr->bitstream_id>10){
+ /* Enhanced AC-3 */
+ skip_bits(gbc, 5); // skip bitstream id
+
+ /* skip dialog normalization and compression gain */
+ for (i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
+ skip_bits(gbc, 5); // skip dialog normalization
+ if (get_bits1(gbc)) {
+ skip_bits(gbc, 8); //skip Compression gain word
+ }
+ }
+ /* dependent stream channel map */
+ if (hdr->frame_type == EAC3_FRAME_TYPE_DEPENDENT && get_bits1(gbc)) {
+ hdr->channel_map = get_bits(gbc, 16); //custom channel map
+ return 0;
+ }
+ }
+ //default channel map based on acmod and lfeon
+ hdr->channel_map = ff_eac3_default_chmap[hdr->channel_mode];
+ if(hdr->lfe_on)
+ hdr->channel_map |= AC3_CHMAP_LFE;
+ }
+ return ret;
+}
+
+static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
+ int *need_next_header, int *new_frame_start)
{
int err;
+ union {
+ uint64_t u64;
+ uint8_t u8[8];
+ } tmp = { be2me_64(state) };
AC3HeaderInfo hdr;
+ GetBitContext gbc;
- err = ff_ac3_parse_header(hdr_info->inbuf, &hdr);
+ init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
+ err = ff_ac3_parse_header(&gbc, &hdr);
if(err < 0)
return 0;
hdr_info->sample_rate = hdr.sample_rate;
hdr_info->bit_rate = hdr.bit_rate;
hdr_info->channels = hdr.channels;
- hdr_info->samples = AC3_FRAME_SIZE;
-
- switch(hdr.frame_type){
- case EAC3_FRAME_TYPE_INDEPENDENT:
- *flag = FRAME_START;
- break;
- case EAC3_FRAME_TYPE_DEPENDENT:
- *flag = FRAME_CONTINUATION;
- break;
- case EAC3_FRAME_TYPE_AC3_CONVERT:
- *flag = FRAME_COMPLETE;
- break;
- }
+ hdr_info->channel_layout = hdr.channel_layout;
+ hdr_info->samples = hdr.num_blocks * 256;
+ if(hdr.bitstream_id>10)
+ hdr_info->codec_id = CODEC_ID_EAC3;
+ else
+ hdr_info->codec_id = 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 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 },
+ { CODEC_ID_AC3, CODEC_ID_EAC3 },
sizeof(AACAC3ParseContext),
ac3_parse_init,
ff_aac_ac3_parse,
- NULL,
+ ff_parse_close,
};
projects / ffmpeg / blobdiff