/*****************************************************************************
* FUNCTION
* daf_seek
* DESCRIPTION
*
* PARAMETERS
* input_stream [?]
* offset [?]
* aud_info_struct *info_p(?)
* RETURNS
* kal_bool
*****************************************************************************/
kal_bool daf_seek(audio_input_stream_struct *input_stream, kal_uint32 *offset)
{
/*----------------------------------------------------------------*/
/* Local Variables */
/*----------------------------------------------------------------*/
kal_int32 v2_tag_size;
/*----------------------------------------------------------------*/
/* Code Body */
/*----------------------------------------------------------------*/
if (*offset == 0)
{
/* skip id3v2 tag */
if (audio_input_stream_read(input_stream, 10) != 10)
{
return KAL_FALSE;
}
if ((v2_tag_size = id3_tag_parse_v2_tag_size(input_stream->ptr)) > 0)
{
*offset = v2_tag_size;
}
}
audio_input_stream_seek(input_stream, (kal_int32) * offset);
if (!daf_parse(input_stream, offset, NULL))
{
return KAL_FALSE;
}
audio_input_stream_seek(input_stream, (kal_int32) * offset);
return KAL_TRUE;
}
/*****************************************************************************
* FUNCTION
* daf_check_next_frame
* DESCRIPTION
*
* IMPACT
*
* PARAMETERS
* audio_input_stream_struct *input_stream
* daf_header_struct* prev_header
* kal_int32 min_next_pos
* kal_int32 max_next_pos
* kal_int32 *next_pos
* RETURNS
* kal_uint8 : DAF_CHECK_NEXT_FRAME_RESULT_ENUM
* GLOBALS AFFECTED
*
*****************************************************************************/
kal_uint8 daf_check_next_frame( audio_input_stream_struct *input_stream, daf_header_struct* prev_header, kal_int32 min_next_pos, kal_int32 max_next_pos, kal_int32 *next_pos )
{
daf_header_struct header;
kal_int32 search_pos;
kal_uint8 search_count;
if( (kal_uint32)max_next_pos + 4 > input_stream->total_load ) // check if enough space for decoding next frame header
{
// refill buffer
audio_input_stream_read( input_stream, 0 );
if( (kal_uint32)max_next_pos + 4 > input_stream->total_load ) // check if still have enough space
return DAF_CHECK_FRAME_EOF; // eof
}
// check if it's a valid frame header
for( search_count = 0; search_count < 2; search_count++ )
{
if( search_count == 0 )
search_pos = max_next_pos;
else
search_pos = min_next_pos;
if( daf_parse_frame_header( input_stream->tail + search_pos - input_stream->total_load, &header ) )
{
if( prev_header->version == header.version && prev_header->layer == header.layer &&
prev_header->channel_num == header.channel_num && prev_header->sample_rate == header.sample_rate )
{
*next_pos = search_pos;
return DAF_CHECK_FRAME_TRUE;
}
}
}
return DAF_CHECK_FRAME_FALSE;
}
/*****************************************************************************
* FUNCTION
* daf_check_next_frame
* DESCRIPTION
*
* PARAMETERS
* input_stream [?]
* prev_header [?]
* min_next_pos [IN]
* max_next_pos [IN]
* next_pos [?]
* RETURNS
* kal_uint8 : DAF_CHECK_NEXT_FRAME_RESULT_ENUM
*****************************************************************************/
kal_uint8 daf_check_next_frame(
audio_input_stream_struct *input_stream,
daf_header_struct *prev_header,
kal_int32 min_next_pos,
kal_int32 max_next_pos,
kal_int32 *next_pos)
{
/*----------------------------------------------------------------*/
/* Local Variables */
/*----------------------------------------------------------------*/
daf_header_struct header;
kal_int32 search_pos;
kal_uint8 search_count;
/*----------------------------------------------------------------*/
/* Code Body */
/*----------------------------------------------------------------*/
if ((kal_uint32) max_next_pos + 4 > input_stream->total_load) /* check if enough space for decoding next frame header */
{
/* refill buffer */
audio_input_stream_read(input_stream, 0);
if ((kal_uint32) max_next_pos + 4 > input_stream->total_load) /* check if still have enough space */
{
return DAF_CHECK_FRAME_EOF; /* eof */
}
}
/* check if it's a valid frame header */
for (search_count = 0; search_count < 2; search_count++)
{
if (search_count == 0)
{
search_pos = max_next_pos;
}
else
{
search_pos = min_next_pos;
}
if (daf_parse_frame_header(input_stream->tail + search_pos - input_stream->total_load, &header))
{
if (prev_header->version == header.version && prev_header->layer == header.layer &&
prev_header->channel_num == header.channel_num && prev_header->sample_rate == header.sample_rate)
{
*next_pos = search_pos;
return DAF_CHECK_FRAME_TRUE;
}
}
}
return DAF_CHECK_FRAME_FALSE;
}
/*****************************************************************************
* FUNCTION
* daf_seek
* DESCRIPTION
*
* IMPACT
*
* PARAMETERS
* aud_info_struct *info_p
* kal_uint32* offset
* RETURNS
* kal_bool
* GLOBALS AFFECTED
*
*****************************************************************************/
kal_bool daf_seek( audio_input_stream_struct *input_stream, kal_uint32* offset )
{
kal_int32 v2_tag_size;
if( *offset == 0 )
{
// skip id3v2 tag
if( audio_input_stream_read( input_stream, 10 ) != 10 )
return KAL_FALSE;
if( ( v2_tag_size = id3_tag_parse_v2_tag_size( input_stream->ptr )) > 0 )
*offset = v2_tag_size;
}
audio_input_stream_seek( input_stream, (kal_int32) *offset );
if( !daf_parse( input_stream, offset, NULL ) )
return KAL_FALSE;
audio_input_stream_seek( input_stream, (kal_int32) *offset );
return KAL_TRUE;
}
/*****************************************************************************
* FUNCTION
* daf_find_next_frame
* DESCRIPTION
*
* PARAMETERS
* input_stream [?]
* header [?]
* move_offset [IN]
* RETURNS
* kal_bool
*****************************************************************************/
kal_bool daf_find_next_frame(
audio_input_stream_struct *input_stream,
daf_header_struct *header,
kal_uint32 move_offset)
{
/*----------------------------------------------------------------*/
/* Local Variables */
/*----------------------------------------------------------------*/
daf_header_struct free_bitrate_header;
kal_uint32 round, read_size;
kal_uint32 sample_rate, bitrate, frame_slots, channel_num;
kal_uint8 layer, version, slot_bytes;
kal_uint8 *ptr, *end;
kal_uint8 result = DAF_FIND_FRAME_FALSE;
/*----------------------------------------------------------------*/
/* Code Body */
/*----------------------------------------------------------------*/
for (round = 0; result != DAF_FIND_FRAME_TRUE; round++)
{
/* check if it is out of searching range */
if (input_stream->total_load > input_stream->skip + DAF_FRAME_CHECK_SIZE)
{
return KAL_FALSE;
}
/* refill data */
audio_input_stream_read(input_stream, 0);
read_size = input_stream->tail - input_stream->ptr;
if (round == 0)
{
if (read_size < 4 + move_offset) /* we need at least 4 + move_offset bytes to check frame header */
{
return KAL_FALSE; /* eof */
}
input_stream->ptr += move_offset;
}
else if (read_size < 4) /* we need at least 4 bytes to check frame header */
{
return KAL_FALSE; /* eof */
}
if (result == DAF_FIND_FRAME_FREE_BITRATE)
{
/* search next frame for calculating free bitrate */
bitrate = 0;
version = header->version;
layer = header->layer;
sample_rate = header->sample_rate;
channel_num = header->channel_num;
for (ptr = input_stream->ptr + 4, end = input_stream->tail - 4; ptr <= end; ptr++)
{
/* check if ptr reference to a valid frame header */
if (daf_parse_frame_header(ptr, &free_bitrate_header))
{
if (version == free_bitrate_header.version &&
layer == free_bitrate_header.layer &&
sample_rate == free_bitrate_header.sample_rate &&
bitrate == free_bitrate_header.bitrate && channel_num == free_bitrate_header.channel_num)
{
slot_bytes = 1;
if (layer == DAF_LAYER_I)
{
frame_slots = 12;
slot_bytes = 4;
}
else if ((layer == DAF_LAYER_III) && (version == DAF_VERSION_2 || version == DAF_VERSION_2_5))
{
frame_slots = 72;
}
else
{
frame_slots = 144;
}
header->min_frame_size = header->max_frame_size = ptr - input_stream->ptr;
bitrate = (header->min_frame_size / slot_bytes) * sample_rate / frame_slots;
if (bitrate >= 8000 && !(layer == DAF_LAYER_III && bitrate > 640000))
{
header->bitrate = input_stream->free_bitrate = bitrate;
input_stream->ptr = ptr;
return KAL_TRUE;
}
}
// if the latest found frame header doesn't match with the previous frame header,
// we discard the previous one, and use the latest found frame header
memcpy(header, &free_bitrate_header, sizeof(daf_header_struct));
bitrate = header->bitrate;
layer = header->layer;
if (header->bitrate != 0)
{
result = DAF_FIND_FRAME_TRUE;
}
break;
}
}
input_stream->ptr = ptr;
}
else
{
/* loop through all data in input_stream */
for (ptr = input_stream->ptr, end = input_stream->tail - 4; ptr <= end; ptr++)
{
/* check if ptr reference to a valid frame header */
if (daf_parse_frame_header(ptr, header))
{
result = DAF_FIND_FRAME_TRUE;
/* check if it's free bitrate */
if (header->bitrate == 0)
{
if (input_stream->free_bitrate == 0)
{
result = DAF_FIND_FRAME_FREE_BITRATE;
}
else
{
header->bitrate = input_stream->free_bitrate;
/* calculate frame length */
version = header->version;
layer = header->layer;
slot_bytes = 1;
if (layer == DAF_LAYER_I)
{
frame_slots = 12;
slot_bytes = 4;
}
else if ((layer == DAF_LAYER_III) &&
(version == DAF_VERSION_2 || version == DAF_VERSION_2_5))
{
frame_slots = 72;
}
else
{
frame_slots = 144;
}
header->min_frame_size = (frame_slots * header->bitrate / header->sample_rate) * slot_bytes;
header->max_frame_size = header->min_frame_size + slot_bytes;
}
}
break;
}
}
input_stream->ptr = ptr;
}
}
return KAL_TRUE;
}
