static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
{
int64_t dts;
uint8_t header[FRAME_HEADER_SIZE+4];
int header_size = FRAME_HEADER_SIZE;
dts = s->timestamp + pkt->dts;
/* packet size & key_frame */
header[0] = pkt->stream_index;
header[1] = 0;
if (pkt->flags & PKT_FLAG_KEY)
header[1] |= FLAG_KEY_FRAME;
AV_WB24(header+2, pkt->size);
AV_WB24(header+5, pkt->duration);
AV_WB64(header+8, s->timestamp + pkt->pts);
if (pkt->pts != pkt->dts) {
header[1] |= FLAG_DTS;
AV_WB32(header+16, pkt->pts - pkt->dts);
header_size += 4;
}
ffm_write_data(s, header, header_size, dts, 1);
ffm_write_data(s, pkt->data, pkt->size, dts, 0);
return 0;
}
static void create_iv(uint8_t *iv, const uint8_t *salt, uint64_t index,
uint32_t ssrc)
{
uint8_t indexbuf[8];
int i;
memset(iv, 0, 16);
AV_WB32(&iv[4], ssrc);
AV_WB64(indexbuf, index);
for (i = 0; i < 8; i++) // index << 16
iv[6 + i] ^= indexbuf[i];
for (i = 0; i < 14; i++)
iv[i] ^= salt[i];
}
static int aac_sync(uint64_t state, AACAC3ParseContext *hdr_info,
int *need_next_header, int *new_frame_start)
{
GetBitContext bits;
int size, rdb, ch, sr;
uint8_t tmp[8];
AV_WB64(tmp, state);
init_get_bits(&bits, tmp+8-AAC_HEADER_SIZE, AAC_HEADER_SIZE * 8);
if(get_bits(&bits, 12) != 0xfff)
return 0;
skip_bits1(&bits); /* id */
skip_bits(&bits, 2); /* layer */
skip_bits1(&bits); /* protection_absent */
skip_bits(&bits, 2); /* profile_objecttype */
sr = get_bits(&bits, 4); /* sample_frequency_index */
if(!ff_mpeg4audio_sample_rates[sr])
return 0;
skip_bits1(&bits); /* private_bit */
ch = get_bits(&bits, 3); /* channel_configuration */
if(!ff_mpeg4audio_channels[ch])
return 0;
skip_bits1(&bits); /* original/copy */
skip_bits1(&bits); /* home */
/* adts_variable_header */
skip_bits1(&bits); /* copyright_identification_bit */
skip_bits1(&bits); /* copyright_identification_start */
size = get_bits(&bits, 13); /* aac_frame_length */
if(size < AAC_HEADER_SIZE)
return 0;
skip_bits(&bits, 11); /* adts_buffer_fullness */
rdb = get_bits(&bits, 2); /* number_of_raw_data_blocks_in_frame */
hdr_info->channels = ff_mpeg4audio_channels[ch];
hdr_info->sample_rate = ff_mpeg4audio_sample_rates[sr];
hdr_info->samples = (rdb + 1) * 1024;
hdr_info->bit_rate = size * 8 * hdr_info->sample_rate / hdr_info->samples;
*need_next_header = 0;
*new_frame_start = 1;
return size;
}