コード例 #1
0
vod_status_t
manifest_utils_build_request_params_string(
	request_context_t* request_context,
	uint32_t* has_tracks,
	uint32_t segment_index,
	uint32_t sequences_mask,
	uint32_t* sequence_tracks_mask,
	uint32_t* tracks_mask,
	vod_str_t* suffix,
	vod_str_t* args_str,
	vod_str_t* result)
{
	u_char* p;
	size_t result_size;
	bool_t newline_shift = FALSE;

	if (sequence_tracks_mask != NULL)
	{
		return manifest_utils_build_request_params_string_per_sequence_tracks(
			request_context,
			segment_index,
			sequences_mask,
			sequence_tracks_mask,
			result);
	}

	result_size = suffix->len + args_str->len;

	if (suffix->data[suffix->len - 1] == '\n')
	{
		newline_shift = TRUE;
	}

	// segment index
	if (segment_index != INVALID_SEGMENT_INDEX)
	{
		result_size += 1 + vod_get_int_print_len(segment_index + 1);
	}

	// sequence mask
	if (sequences_mask != 0xffffffff)
	{
		 result_size += vod_get_number_of_set_bits(sequences_mask) * (sizeof("-f32") - 1);
	}

	// video tracks
	if (tracks_mask[MEDIA_TYPE_VIDEO] == 0xffffffff)
	{
		result_size += sizeof("-v0") - 1;
	}
	else
	{
		result_size += vod_get_number_of_set_bits(tracks_mask[MEDIA_TYPE_VIDEO]) * (sizeof("-v32") - 1);
	}

	// audio tracks
	if (tracks_mask[MEDIA_TYPE_AUDIO] == 0xffffffff)
	{
		result_size += sizeof("-a0") - 1;
	}
	else
	{
		result_size += vod_get_number_of_set_bits(tracks_mask[MEDIA_TYPE_AUDIO]) * (sizeof("-a32") - 1);
	}

	p = vod_alloc(request_context->pool, result_size + 1);
	if (p == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"manifest_utils_build_request_params_string: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}
	result->data = p;

	// segment index
	if (segment_index != INVALID_SEGMENT_INDEX)
	{
		p = vod_sprintf(p, "-%uD", segment_index + 1);
	}

	// sequence mask
	if (sequences_mask != 0xffffffff)
	{
		p = manifest_utils_write_bitmask(p, sequences_mask, 'f');
	}

	// video tracks
	if (has_tracks[MEDIA_TYPE_VIDEO])
	{
		if (tracks_mask[MEDIA_TYPE_VIDEO] == 0xffffffff)
		{
			p = vod_copy(p, "-v0", sizeof("-v0") - 1);
		}
		else
		{
			p = manifest_utils_write_bitmask(p, tracks_mask[MEDIA_TYPE_VIDEO], 'v');
		}
	}

	// audio tracks
	if (has_tracks[MEDIA_TYPE_AUDIO])
	{
		if (tracks_mask[MEDIA_TYPE_AUDIO] == 0xffffffff)
		{
			p = vod_copy(p, "-a0", sizeof("-a0") - 1);
		}
		else
		{
			p = manifest_utils_write_bitmask(p, tracks_mask[MEDIA_TYPE_AUDIO], 'a');
		}
	}

	p = vod_copy(p, suffix->data, newline_shift ? suffix->len - 1 : suffix->len);
	p = vod_copy(p, args_str->data, args_str->len);

	if (newline_shift)
	{
		*p++ = '\n';
	}

	result->len = p - result->data;

	if (result->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"manifest_utils_build_request_params_string: result length %uz exceeded allocated length %uz",
			result->len, result_size);
		return VOD_UNEXPECTED;
	}

	return VOD_OK;
}
コード例 #2
0
static vod_status_t
manifest_utils_build_request_params_string_per_sequence_tracks(
	request_context_t* request_context,
	uint32_t segment_index,
	uint32_t sequences_mask,
	uint32_t* sequence_tracks_mask,
	vod_str_t* result)
{
	u_char* p;
	size_t result_size;
	uint32_t* tracks_mask;
	uint32_t i;

	result_size = 0;

	// segment index
	if (segment_index != INVALID_SEGMENT_INDEX)
	{
		result_size += 1 + vod_get_int_print_len(segment_index + 1);
	}

	for (i = 0, tracks_mask = sequence_tracks_mask;
		i < MAX_SEQUENCES;
		i++, tracks_mask += MEDIA_TYPE_COUNT)
	{
		if ((sequences_mask & (1 << i)) == 0)
		{
			continue;
		}

		// sequence
		result_size += sizeof("-f32") - 1;

		// video tracks
		if (tracks_mask[MEDIA_TYPE_VIDEO] == 0xffffffff)
		{
			result_size += sizeof("-v0") - 1;
		}
		else
		{
			result_size += vod_get_number_of_set_bits(tracks_mask[MEDIA_TYPE_VIDEO]) * (sizeof("-v32") - 1);
		}

		// audio tracks
		if (tracks_mask[MEDIA_TYPE_AUDIO] == 0xffffffff)
		{
			result_size += sizeof("-a0") - 1;
		}
		else
		{
			result_size += vod_get_number_of_set_bits(tracks_mask[MEDIA_TYPE_AUDIO]) * (sizeof("-a32") - 1);
		}
	}

	p = vod_alloc(request_context->pool, result_size + 1);
	if (p == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"manifest_utils_build_request_params_string_per_sequence_tracks: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}
	result->data = p;

	// segment index
	if (segment_index != INVALID_SEGMENT_INDEX)
	{
		p = vod_sprintf(p, "-%uD", segment_index + 1);
	}

	for (i = 0, tracks_mask = sequence_tracks_mask;
		i < MAX_SEQUENCES;
		i++, tracks_mask += MEDIA_TYPE_COUNT)
	{
		if ((sequences_mask & (1 << i)) == 0)
		{
			continue;
		}

		// sequence
		p = vod_sprintf(p, "-f%uD", i + 1);

		// video tracks
		switch (tracks_mask[MEDIA_TYPE_VIDEO])
		{
		case 0xffffffff:
			p = vod_copy(p, "-v0", sizeof("-v0") - 1);
			break;

		case 0:
			break;

		default:
			p = manifest_utils_write_bitmask(p, tracks_mask[MEDIA_TYPE_VIDEO], 'v');
			break;
		}

		// audio tracks
		switch (tracks_mask[MEDIA_TYPE_AUDIO])
		{
		case 0xffffffff:
			p = vod_copy(p, "-a0", sizeof("-a0") - 1);
			break;

		case 0:
			break;

		default:
			p = manifest_utils_write_bitmask(p, tracks_mask[MEDIA_TYPE_AUDIO], 'a');
			break;
		}
	}

	result->len = p - result->data;

	if (result->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"manifest_utils_build_request_params_string_per_sequence_tracks: result length %uz exceeded allocated length %uz",
			result->len, result_size);
		return VOD_UNEXPECTED;
	}

	return VOD_OK;
}
コード例 #3
0
static vod_status_t
m3u8_builder_build_required_tracks_string(
	request_context_t* request_context, 
	media_set_t* media_set,
	uint32_t sequence_index,
	request_params_t* request_params,
	vod_str_t* tracks_spec)
{
	u_char* p;
	size_t result_size;
	uint32_t i;

	result_size = 0;
	if (request_params->tracks_mask[MEDIA_TYPE_VIDEO] != 0xffffffff)
	{
		result_size += vod_get_number_of_set_bits(request_params->tracks_mask[MEDIA_TYPE_VIDEO]) * (sizeof("-v32") - 1);
	}
	if (request_params->tracks_mask[MEDIA_TYPE_AUDIO] != 0xffffffff)
	{
		result_size += vod_get_number_of_set_bits(request_params->tracks_mask[MEDIA_TYPE_AUDIO]) * (sizeof("-a32") - 1);
	}
	if (sequence_index != INVALID_SEQUENCE_INDEX)
	{
		result_size += sizeof("-f") - 1 + vod_get_int_print_len(sequence_index + 1);
	}

	p = vod_alloc(request_context->pool, result_size + 1);
	if (p == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"m3u8_builder_build_required_tracks_string: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}
	tracks_spec->data = p;

	if (sequence_index != INVALID_SEQUENCE_INDEX)
	{
		p = vod_sprintf(p, "-f%uD", sequence_index + 1);
	}

	if (media_set->track_count[MEDIA_TYPE_VIDEO] != 0)
	{
		if (request_params->tracks_mask[MEDIA_TYPE_VIDEO] == 0xffffffff)
		{
			p = vod_copy(p, "-v0", sizeof("-v0") - 1);
		}
		else
		{
			for (i = 0; i < 32; i++)
			{
				if ((request_params->tracks_mask[MEDIA_TYPE_VIDEO] & (1 << i)) == 0)
				{
					continue;
				}

				p = vod_sprintf(p, "-v%uD", i + 1);
			}
		}
	}
	
	if (media_set->track_count[MEDIA_TYPE_AUDIO] != 0)
	{
		if (request_params->tracks_mask[MEDIA_TYPE_AUDIO] == 0xffffffff)
		{
			p = vod_copy(p, "-a0", sizeof("-a0") - 1);
		}
		else
		{
			for (i = 0; i < 32; i++)
			{
				if ((request_params->tracks_mask[MEDIA_TYPE_AUDIO] & (1 << i)) == 0)
				{
					continue;
				}

				p = vod_sprintf(p, "-a%uD", i + 1);
			}
		}
	}

	tracks_spec->len = p - tracks_spec->data;

	if (tracks_spec->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_required_tracks_string: result length %uz exceeded allocated length %uz", 
			tracks_spec->len, result_size);
		return VOD_UNEXPECTED;
	}
	
	return VOD_OK;
}
コード例 #4
0
vod_status_t
m3u8_builder_build_index_playlist(
	request_context_t* request_context,
	m3u8_config_t* conf,
	vod_str_t* base_url,
	vod_str_t* segments_base_url,
	request_params_t* request_params,
	hls_encryption_params_t* encryption_params,
	media_set_t* media_set,
	vod_str_t* result)
{
	segment_durations_t segment_durations;
	segment_duration_item_t* cur_item;
	segment_duration_item_t* last_item;
	segmenter_conf_t* segmenter_conf = media_set->segmenter_conf;
	uint64_t duration_millis;
	uint32_t sequence_index;
	vod_str_t extinf;
	uint32_t segment_index;
	uint32_t last_segment_index;
	vod_str_t tracks_spec;
	uint32_t scale;
	size_t segment_length;
	size_t result_size;
	vod_status_t rc;
	u_char* p;

	sequence_index = media_set->has_multi_sequences ? media_set->sequences[0].index : INVALID_SEQUENCE_INDEX;

	// build the required tracks string
	rc = m3u8_builder_build_required_tracks_string(
		request_context,
		media_set,
		sequence_index,
		request_params,
		&tracks_spec);
	if (rc != VOD_OK)
	{
		return rc;
	}

	// get the segment durations
	rc = segmenter_conf->get_segment_durations(
		request_context,
		segmenter_conf,
		media_set,
		NULL,
		MEDIA_TYPE_NONE,
		&segment_durations);
	if (rc != VOD_OK)
	{
		return rc;
	}

	// get the required buffer length
	duration_millis = segment_durations.end_time - segment_durations.start_time;
	last_segment_index = media_set->initial_segment_index + segment_durations.segment_count;
	segment_length = sizeof("#EXTINF:.000,\n") - 1 + vod_get_int_print_len(vod_div_ceil(duration_millis, 1000)) +
		segments_base_url->len + conf->segment_file_name_prefix.len + 1 + vod_get_int_print_len(last_segment_index) + tracks_spec.len + sizeof(".ts\n") - 1;

	result_size =
		sizeof(M3U8_HEADER_PART1) + VOD_INT64_LEN +
		sizeof(M3U8_HEADER_VOD) +
		sizeof(M3U8_HEADER_PART2) + VOD_INT64_LEN + VOD_INT32_LEN +
		segment_length * segment_durations.segment_count +
		segment_durations.discontinuities * (sizeof(m3u8_discontinuity) - 1) +
		sizeof(m3u8_footer);

	if (encryption_params->type != HLS_ENC_NONE)
	{
		result_size +=
			sizeof(encryption_key_tag_part1) - 1 +
			sizeof(encryption_type_sample_aes) - 1 +
			sizeof(encryption_key_tag_part2) - 1 +
			base_url->len +
			conf->encryption_key_file_name.len +
			sizeof("-f") - 1 + VOD_INT32_LEN +
			sizeof(encryption_key_tag_part3) - 1;
	}

	// allocate the buffer
	result->data = vod_alloc(request_context->pool, result_size);
	if (result->data == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"m3u8_builder_build_index_playlist: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}

	// write the header
	p = vod_sprintf(
		result->data,
		M3U8_HEADER_PART1,
		(segmenter_conf->max_segment_duration + 500) / 1000);

	if (media_set->type == MEDIA_SET_VOD)
	{
		p = vod_copy(p, M3U8_HEADER_VOD, sizeof(M3U8_HEADER_VOD) - 1);
	}

	if (encryption_params->type != HLS_ENC_NONE)
	{
		p = vod_copy(p, encryption_key_tag_part1, sizeof(encryption_key_tag_part1) - 1);
		switch (encryption_params->type)
		{
		case HLS_ENC_SAMPLE_AES:
			p = vod_copy(p, encryption_type_sample_aes, sizeof(encryption_type_sample_aes) - 1);
			break;

		default:		// HLS_ENC_AES_128
			p = vod_copy(p, encryption_type_aes_128, sizeof(encryption_type_aes_128) - 1);
			break;
		}
		p = vod_copy(p, encryption_key_tag_part2, sizeof(encryption_key_tag_part2) - 1);
		p = vod_copy(p, base_url->data, base_url->len);
		p = vod_copy(p, conf->encryption_key_file_name.data, conf->encryption_key_file_name.len);
		if (sequence_index != INVALID_SEQUENCE_INDEX)
		{
			p = vod_sprintf(p, "-f%uD", sequence_index + 1);
		}
		p = vod_copy(p, encryption_key_tag_part3, sizeof(encryption_key_tag_part3) - 1);
	}

	p = vod_sprintf(
		p,
		M3U8_HEADER_PART2,
		conf->m3u8_version, 
		media_set->initial_segment_index + 1);

	// write the segments
	scale = conf->m3u8_version >= 3 ? 1000 : 1;
	last_item = segment_durations.items + segment_durations.item_count;

	for (cur_item = segment_durations.items; cur_item < last_item; cur_item++)
	{
		segment_index = cur_item->segment_index;
		last_segment_index = segment_index + cur_item->repeat_count;

		if (cur_item->discontinuity)
		{
			p = vod_copy(p, m3u8_discontinuity, sizeof(m3u8_discontinuity) - 1);
		}

		// write the first segment
		extinf.data = p;
		p = m3u8_builder_append_extinf_tag(p, rescale_time(cur_item->duration, segment_durations.timescale, scale), scale);
		extinf.len = p - extinf.data;
		p = m3u8_builder_append_segment_name(p, segments_base_url, &conf->segment_file_name_prefix, segment_index, &tracks_spec);
		segment_index++;

		// write any additional segments
		for (; segment_index < last_segment_index; segment_index++)
		{
			p = vod_copy(p, extinf.data, extinf.len);
			p = m3u8_builder_append_segment_name(p, segments_base_url, &conf->segment_file_name_prefix, segment_index, &tracks_spec);
		}
	}

	// write the footer
	if (media_set->type == MEDIA_SET_VOD)
	{
		p = vod_copy(p, m3u8_footer, sizeof(m3u8_footer) - 1);
	}

	result->len = p - result->data;

	if (result->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_index_playlist: result length %uz exceeded allocated length %uz", 
			result->len, result_size);
		return VOD_UNEXPECTED;
	}
	
	return VOD_OK;
}
コード例 #5
0
vod_status_t
m3u8_builder_build_iframe_playlist(
	request_context_t* request_context,
	m3u8_config_t* conf,
	hls_muxer_conf_t* muxer_conf,
	vod_str_t* base_url,
	request_params_t* request_params,
	media_set_t* media_set,
	vod_str_t* result)
{
	hls_encryption_params_t encryption_params;
	write_segment_context_t ctx;
	segment_durations_t segment_durations;
	segmenter_conf_t* segmenter_conf = media_set->segmenter_conf;
	size_t iframe_length;
	size_t result_size;
	uint64_t duration_millis;
	uint32_t sequence_index;
	vod_status_t rc; 

	sequence_index = media_set->has_multi_sequences ? media_set->sequences[0].index : INVALID_SEQUENCE_INDEX;

	// iframes list is not supported with encryption, since:
	// 1. AES-128 - the IV of each key frame is not known in advance
	// 2. SAMPLE-AES - the layout of the TS files is not known in advance due to emulation prevention
	encryption_params.type = HLS_ENC_NONE;
	encryption_params.key = NULL;
	encryption_params.iv = NULL;

	// build the required tracks string
	rc = m3u8_builder_build_required_tracks_string(
		request_context, 
		media_set,
		sequence_index,
		request_params,
		&ctx.tracks_spec);
	if (rc != VOD_OK)
	{
		return rc;
	}

	// get segment durations
	if (segmenter_conf->align_to_key_frames)
	{
		rc = segmenter_get_segment_durations_accurate(
			request_context,
			segmenter_conf,
			media_set,
			NULL,
			MEDIA_TYPE_NONE,
			&segment_durations);
	}
	else
	{
		rc = segmenter_get_segment_durations_estimate(
			request_context,
			segmenter_conf,
			media_set,
			NULL,
			MEDIA_TYPE_NONE,
			&segment_durations);
	}

	if (rc != VOD_OK)
	{
		return rc;
	}

	duration_millis = segment_durations.end_time - segment_durations.start_time;
	iframe_length = sizeof("#EXTINF:.000,\n") - 1 + vod_get_int_print_len(vod_div_ceil(duration_millis, 1000)) +
		sizeof(byte_range_tag_format) + VOD_INT32_LEN + vod_get_int_print_len(MAX_FRAME_SIZE) - (sizeof("%uD%uD") - 1) +
		base_url->len + conf->segment_file_name_prefix.len + 1 + vod_get_int_print_len(segment_durations.segment_count) + ctx.tracks_spec.len + sizeof(".ts\n") - 1;

	result_size =
		conf->iframes_m3u8_header_len +
		iframe_length * media_set->sequences[0].video_key_frame_count +
		sizeof(m3u8_footer);

	// allocate the buffer
	result->data = vod_alloc(request_context->pool, result_size);
	if (result->data == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"m3u8_builder_build_iframe_playlist: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}

	// fill out the buffer
	ctx.p = vod_copy(result->data, conf->iframes_m3u8_header, conf->iframes_m3u8_header_len);

	if (media_set->sequences[0].video_key_frame_count > 0)
	{
		ctx.base_url = base_url;
		ctx.segment_file_name_prefix = &conf->segment_file_name_prefix;
	
		rc = hls_muxer_simulate_get_iframes(
			request_context,
			&segment_durations, 
			muxer_conf,
			&encryption_params,
			media_set, 
			m3u8_builder_append_iframe_string, 
			&ctx);
		if (rc != VOD_OK)
		{
			return rc;
		}
	}

	ctx.p = vod_copy(ctx.p, m3u8_footer, sizeof(m3u8_footer) - 1);
	result->len = ctx.p - result->data;

	if (result->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_iframe_playlist: result length %uz exceeded allocated length %uz", 
			result->len, result_size);
		return VOD_UNEXPECTED;
	}
	
	return VOD_OK;
}
コード例 #6
0
static vod_status_t
m3u8_builder_build_required_tracks_string(
	request_context_t* request_context, 
	bool_t include_file_index,
	mpeg_metadata_t* mpeg_metadata, 
	vod_str_t* required_tracks)
{
	mpeg_stream_metadata_t* cur_stream;
	uint32_t printed_file_indexes;
	uint32_t file_index;
	u_char* p;
	size_t result_size;

	result_size = mpeg_metadata->streams.nelts * (sizeof("-v") - 1 + vod_get_int_print_len(mpeg_metadata->max_track_index + 1));
	if (include_file_index)
	{
		result_size += mpeg_metadata->streams.nelts * (sizeof("-f") - 1 + vod_get_int_print_len(mpeg_metadata->first_stream->file_info.file_index + 1));
	}
	p = vod_alloc(request_context->pool, result_size + 1);
	if (p == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"m3u8_builder_build_required_tracks_string: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}
	required_tracks->data = p;

	if (include_file_index)
	{
		printed_file_indexes = 0;
		for (cur_stream = mpeg_metadata->first_stream; cur_stream < mpeg_metadata->last_stream; cur_stream++)
		{
			file_index = cur_stream->file_info.file_index;
			if ((printed_file_indexes & (1 << file_index)) != 0)
			{
				continue;
			}

			p = vod_sprintf(p, "-f%uD", file_index + 1);
			printed_file_indexes |= (1 << file_index);
		}
	}

	for (cur_stream = mpeg_metadata->first_stream; cur_stream < mpeg_metadata->last_stream; cur_stream++)
	{
		*p++ = '-';
		switch (cur_stream->media_info.media_type)
		{
		case MEDIA_TYPE_VIDEO:
			*p++ = 'v';
			break;

		case MEDIA_TYPE_AUDIO:
			*p++ = 'a';
			break;

		default:
			continue;
		}

		p = vod_sprintf(p, "%uD", cur_stream->track_index + 1);
	}
	
	required_tracks->len = p - required_tracks->data;

	if (required_tracks->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_required_tracks_string: result length %uz exceeded allocated length %uz", 
			required_tracks->len, result_size);
		return VOD_UNEXPECTED;
	}

	return VOD_OK;
}
コード例 #7
0
vod_status_t
m3u8_builder_build_iframe_playlist(
	request_context_t* request_context,
	m3u8_config_t* conf,
	hls_muxer_conf_t* muxer_conf,
	vod_str_t* base_url,
	bool_t include_file_index,
	segmenter_conf_t* segmenter_conf,
	mpeg_metadata_t* mpeg_metadata,
	vod_str_t* result)
{
	hls_encryption_params_t encryption_params;
	write_segment_context_t ctx;
	size_t iframe_length;
	size_t result_size;
	hls_muxer_state_t muxer_state;
	bool_t simulation_supported;
	vod_status_t rc; 
	uint32_t segment_count;

	// iframes list is not supported with encryption, since:
	// 1. AES-128 - the IV of each key frame is not known in advance
	// 2. SAMPLE-AES - the layout of the TS files is not known in advance due to emulation prevention
	encryption_params.type = HLS_ENC_NONE;
	encryption_params.key = NULL;
	encryption_params.iv = NULL;

	// initialize the muxer
	rc = hls_muxer_init(
		&muxer_state, 
		request_context, 
		muxer_conf, 
		&encryption_params, 
		0, 
		mpeg_metadata, 
		NULL, 
		NULL, 
		NULL, 
		&simulation_supported);
	if (rc != VOD_OK)
	{
		return rc;
	}

	if (!simulation_supported)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_iframe_playlist: simulation not supported for this file, cant create iframe playlist");
		return VOD_BAD_REQUEST;
	}

	// build the required tracks string
	rc = m3u8_builder_build_required_tracks_string(
		request_context, 
		include_file_index,
		mpeg_metadata, 
		&ctx.required_tracks);
	if (rc != VOD_OK)
	{
		return rc;
	}

	// calculate the required buffer length
	segment_count = segmenter_conf->get_segment_count(segmenter_conf, mpeg_metadata->duration_millis);
	if (segment_count == INVALID_SEGMENT_COUNT)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_iframe_playlist: segment count is invalid");
		return VOD_BAD_DATA;
	}

	iframe_length = sizeof("#EXTINF:.000,\n") - 1 + vod_get_int_print_len(vod_div_ceil(mpeg_metadata->duration_millis, 1000)) +
		sizeof(byte_range_tag_format) + VOD_INT32_LEN + vod_get_int_print_len(MAX_FRAME_SIZE) - (sizeof("%uD%uD") - 1) +
		base_url->len + conf->segment_file_name_prefix.len + 1 + vod_get_int_print_len(segment_count) + ctx.required_tracks.len + sizeof(".ts\n") - 1;

	result_size =
		conf->iframes_m3u8_header_len +
		iframe_length * mpeg_metadata->video_key_frame_count +
		sizeof(m3u8_footer);

	// allocate the buffer
	result->data = vod_alloc(request_context->pool, result_size);
	if (result->data == NULL)
	{
		vod_log_debug0(VOD_LOG_DEBUG_LEVEL, request_context->log, 0,
			"m3u8_builder_build_iframe_playlist: vod_alloc failed");
		return VOD_ALLOC_FAILED;
	}

	// fill out the buffer
	ctx.p = vod_copy(result->data, conf->iframes_m3u8_header, conf->iframes_m3u8_header_len);

	if (mpeg_metadata->video_key_frame_count > 0)
	{
		ctx.base_url = base_url;
		ctx.segment_file_name_prefix = &conf->segment_file_name_prefix;
	
		rc = hls_muxer_simulate_get_iframes(&muxer_state, segmenter_conf, mpeg_metadata, m3u8_builder_append_iframe_string, &ctx);
		if (rc != VOD_OK)
		{
			return rc;
		}
	}

	ctx.p = vod_copy(ctx.p, m3u8_footer, sizeof(m3u8_footer) - 1);
	result->len = ctx.p - result->data;

	if (result->len > result_size)
	{
		vod_log_error(VOD_LOG_ERR, request_context->log, 0,
			"m3u8_builder_build_iframe_playlist: result length %uz exceeded allocated length %uz", 
			result->len, result_size);
		return VOD_UNEXPECTED;
	}
	
	return VOD_OK;
}