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#include "duration.h"
nsavi::Duration::Duration(nsavi::avi_reader *_reader) : ParserBase(_reader)
{
}
// skips a chunk and updates a parser state variable on error
static int SkipChunk(nsavi::avi_reader *reader, const nsavi::riff_chunk *chunk, nsavi::ParseState &state, uint32_t *bytes_read)
{
int ret = nsavi::skip_chunk(reader, chunk, bytes_read);
if (ret == nsavi::READ_EOF)
{
state = nsavi::NOT_FOUND;
return nsavi::READ_NOT_FOUND;
}
else if (ret > nsavi::READ_OK)
{
state = nsavi::PARSE_ERROR;
return ret;
}
else if (ret < nsavi::READ_OK)
{ // pass-thru return value from avi_reader
state = nsavi::PARSE_RESYNC;
return ret;
}
return nsavi::READ_OK;
}
// reads a chunk and updates parse state variable on error
static int ReadChunk(nsavi::avi_reader *reader, nsavi::riff_chunk *chunk, nsavi::ParseState &state, uint32_t *bytes_read)
{
int ret = nsavi::read_riff_chunk(reader, chunk, bytes_read);
if (ret == nsavi::READ_EOF)
{
state = nsavi::NOT_FOUND;
return nsavi::READ_NOT_FOUND;
}
else if (ret > nsavi::READ_OK)
{
state = nsavi::PARSE_ERROR;
return ret;
}
else if (ret < nsavi::READ_OK)
{ // pass-thru return value from avi_reader
state = nsavi::PARSE_RESYNC;
return ret;
}
return nsavi::READ_OK;
}
int nsavi::Duration::GetDuration(int *time_ms)
{
uint32_t riff_type;
int ret = GetRIFFType(&riff_type);
if (ret)
return ret;
if (riff_type != ' IVA')
return READ_INVALID_DATA;
nsavi::HeaderList header_list;
ret = GetHeaderList(&header_list);
if (ret)
return ret;
int duration=-1;
for (uint32_t i=0;i!=header_list.stream_list_size;i++)
{
const nsavi::STRL &stream = header_list.stream_list[i];
if (stream.stream_header)
{
if (stream.stream_header->stream_type == nsavi::stream_type_audio && stream.stream_header->rate)
{
if (stream.stream_header->length && !stream.stream_header->sample_size)
duration = (uint64_t)stream.stream_header->length * (uint64_t)stream.stream_header->scale * 1000ULL / (uint64_t)stream.stream_header->rate;
}
else if (stream.stream_header->stream_type == nsavi::stream_type_video && stream.stream_header->rate)
{
if (duration == -1)
duration = (uint64_t)stream.stream_header->length * (uint64_t)stream.stream_header->scale * 1000ULL / (uint64_t)stream.stream_header->rate;
}
}
}
*time_ms = duration;
return nsavi::READ_OK;
}
int nsavi::Duration::GetHeaderList(HeaderList *header_list)
{
if (riff_parsed != PARSED)
return READ_INVALID_CALL;
if (riff_parsed == PARSE_RESYNC)
reader->Seek(riff_start);
if (header_list_parsed == NOT_READ)
{
// first, see how far we are into the file to properly bound our reads
uint64_t start = reader->Tell();
uint32_t bytes_available = riff_header.size;
bytes_available -= (uint32_t)(start - riff_start);
while (bytes_available)
{
if (bytes_available < 8)
{
header_list_parsed = NOT_FOUND;
return READ_NOT_FOUND;
}
uint32_t bytes_read;
riff_chunk chunk;
int ret = ReadChunk(reader, &chunk, header_list_parsed, &bytes_read);
if (ret)
return ret;
bytes_available -= bytes_read;
if (bytes_available < chunk.size)
{
header_list_parsed = PARSE_ERROR;
return READ_INVALID_DATA;
}
switch(chunk.id)
{
case 'TSIL': // list chunk
switch(chunk.type)
{
case 'lrdh': // this is what we're looking for
ret = ParseHeaderList(chunk.size, &bytes_read);
if (ret == READ_OK)
{
header_list->avi_header = avi_header;
header_list->stream_list = stream_list;
header_list->stream_list_size = stream_list_size;
header_list->odml_header = odml_header;
}
return ret;
default: // skip anything we don't understand
ret = SkipChunk(reader, &chunk, header_list_parsed, &bytes_read);
if (ret)
return ret;
bytes_available -= bytes_read;
break;
}
break;
default: // skip anything we don't understand
case 'KNUJ': // skip junk chunks
ret = SkipChunk(reader, &chunk, header_list_parsed, &bytes_read);
if (ret)
return ret;
bytes_available -= bytes_read;
break;
}
}
}
if (header_list_parsed == PARSED)
{
header_list->avi_header = avi_header;
header_list->stream_list = stream_list;
header_list->stream_list_size = stream_list_size;
header_list->odml_header = odml_header;
return READ_OK;
}
return READ_INVALID_CALL;
}
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