hls: add vod_hls_mpegts_id3_data variable

allows setting the content of the id3 tags returned in segment requests.
for backward compatbility, when the directive is not specified, the
default data is -
`{"timestamp":$vod_segment_time,"sequenceId":"$vod_sequence_id"}`.
also added a new `$vod_segment_time` variable, that can be used with the
new `vod_hls_mpegts_id3_data` directive.

README.md

@@ -1689,8 +1689,19 @@ padding is added as needed.
 * **default**: `off`
 * **context**: `http`, `server`, `location`
 
-When enabled, an ID3 TEXT frame will be outputted in each TS segment, containing a JSON with the absolute segment timestamp.
-The timestamp is measured in milliseconds since the epoch (unixtime x 1000), the JSON structure is: `{"timestamp":1459779115000}`
+When enabled, an ID3 TEXT frame is outputted in each TS segment.
+The content of the ID3 TEXT frame can be set using the directive `vod_hls_mpegts_id3_data`.
+
+#### vod_hls_mpegts_id3_data
+* **syntax**: `vod_hls_mpegts_id3_data string`
+* **default**: `{"timestamp":$vod_segment_time,"sequenceId":"$vod_sequence_id"}`
+* **context**: `http`, `server`, `location`
+
+Sets the data of the ID3 TEXT frame outputted in each TS segment, when `vod_hls_mpegts_output_id3_timestamps` is set to `on`.
+When the directive is not set, the ID3 frames contain by default a JSON object of the format `{"timestamp":1459779115000,"sequenceId":"{id}"}`:
+- `timestamp` - an absolute time measured in milliseconds since the epoch (unixtime x 1000).
+- `sequenceId` - the id field of the sequence object, as specified in the mapping JSON. The field is omitted when the sequence id is empty / not specified in the mapping JSON.
+The parameter value can contain variables.
 
 #### vod_hls_mpegts_align_pts
 * **syntax**: `vod_hls_mpegts_align_pts on/off`
@@ -1821,6 +1832,7 @@ The module adds the following nginx variables:
 	`EXPIRED` - the current server time is larger than `expirationTime`
 	`ALLOC_FAILED` - the module failed to allocate memory
 	`UNEXPECTED` - a scenario that is not supposed to happen, most likely a bug in the module
+* `$vod_segment_time` - for segment requests, contains the absolute timestamp of the first frame in the segment, measured in milliseconds since the epoch (unixtime x 1000).
 * `$vod_segment_duration` - for segment requests, contains the duration of the segment in milliseconds
 * `$vod_frames_bytes_read` - for segment requests, total number of bytes read while processing media frames
 

config

@@ -399,6 +399,7 @@ VOD_SRCS="$VOD_SRCS                                           \
           $ngx_addon_dir/vod/language_code.c                  \
           $ngx_addon_dir/vod/manifest_utils.c                 \
           $ngx_addon_dir/vod/media_format.c                   \
+          $ngx_addon_dir/vod/media_set.c                      \
           $ngx_addon_dir/vod/media_set_parser.c               \
           $ngx_addon_dir/vod/mkv/ebml.c                       \
           $ngx_addon_dir/vod/mkv/mkv_builder.c                \

ngx_http_vod_hls.c

@@ -38,6 +38,10 @@
 
 #define SUPPORTED_CODECS (SUPPORTED_CODECS_MP4 | SUPPORTED_CODECS_TS)
 
+#define ID3_TEXT_JSON_FORMAT "{\"timestamp\":%uL}%Z"
+#define ID3_TEXT_JSON_SEQUENCE_ID_PREFIX_FORMAT "{\"timestamp\":%uL,\"sequenceId\":\""
+#define ID3_TEXT_JSON_SEQUENCE_ID_SUFFIX "\"}"
+
 
 // content types
 static u_char m3u8_content_type[] = "application/vnd.apple.mpegurl";
@@ -266,6 +270,103 @@ ngx_http_vod_hls_init_segment_encryption(
 }
 #endif // NGX_HAVE_OPENSSL_EVP
 
+static ngx_int_t
+ngx_http_vod_hls_get_default_id3_data(ngx_http_vod_submodule_context_t* submodule_context, ngx_str_t* id3_data)
+{
+	media_set_t* media_set;
+	vod_str_t* sequence_id;
+	int64_t timestamp;
+	u_char* p;
+	size_t sequence_id_escape;
+	size_t data_size;
+
+	media_set = &submodule_context->media_set;
+	sequence_id = &media_set->sequences[0].id;
+	if (sequence_id->len != 0)
+	{
+		sequence_id_escape = vod_escape_json(NULL, sequence_id->data, sequence_id->len);
+		data_size = sizeof(ID3_TEXT_JSON_SEQUENCE_ID_PREFIX_FORMAT) + VOD_INT64_LEN +
+			sequence_id->len + sequence_id_escape +
+			sizeof(ID3_TEXT_JSON_SEQUENCE_ID_SUFFIX);
+	}
+	else
+	{
+		sequence_id_escape = 0;
+		data_size = sizeof(ID3_TEXT_JSON_FORMAT) + VOD_INT64_LEN;
+	}
+
+	timestamp = media_set_get_segment_time_millis(media_set);
+
+	p = ngx_pnalloc(submodule_context->request_context.pool, data_size);
+	if (p == NULL)
+	{
+		ngx_log_debug0(NGX_LOG_DEBUG_HTTP, submodule_context->request_context.log, 0,
+			"ngx_http_vod_hls_get_default_id3_data: ngx_pnalloc failed");
+		return ngx_http_vod_status_to_ngx_error(submodule_context->r, VOD_ALLOC_FAILED);
+	}
+
+	id3_data->data = p;
+
+	if (sequence_id->len != 0)
+	{
+		p = vod_sprintf(p, ID3_TEXT_JSON_SEQUENCE_ID_PREFIX_FORMAT, timestamp);
+		if (sequence_id_escape)
+		{
+			p = (u_char*)vod_escape_json(p, sequence_id->data, sequence_id->len);
+		}
+		else
+		{
+			p = vod_copy(p, sequence_id->data, sequence_id->len);
+		}
+		p = vod_copy(p, ID3_TEXT_JSON_SEQUENCE_ID_SUFFIX, sizeof(ID3_TEXT_JSON_SEQUENCE_ID_SUFFIX));
+
+	}
+	else
+	{
+		p = vod_sprintf(p, ID3_TEXT_JSON_FORMAT, timestamp);
+	}
+
+	id3_data->len = p - id3_data->data;
+
+	return NGX_OK;
+}
+
+static ngx_int_t
+ngx_http_vod_hls_init_muxer_conf(ngx_http_vod_submodule_context_t* submodule_context, hls_mpegts_muxer_conf_t* conf)
+{
+	ngx_http_vod_hls_loc_conf_t* hls_conf;
+
+	hls_conf = &submodule_context->conf->hls;
+
+	conf->interleave_frames = hls_conf->interleave_frames;
+	conf->align_frames = hls_conf->align_frames;
+	conf->align_pts = hls_conf->align_pts;
+
+	if (!hls_conf->output_id3_timestamps)
+	{
+		conf->id3_data.data = NULL;
+		conf->id3_data.len = 0;
+		return NGX_OK;
+	}
+
+	if (hls_conf->id3_data != NULL)
+	{
+		if (ngx_http_complex_value(
+			submodule_context->r,
+			hls_conf->id3_data,
+			&conf->id3_data) != NGX_OK)
+		{
+			ngx_log_debug0(NGX_LOG_DEBUG_HTTP, submodule_context->request_context.log, 0,
+				"ngx_http_vod_hls_init_muxer_conf: ngx_http_complex_value failed");
+			return NGX_ERROR;
+		}
+
+		return NGX_OK;
+	}
+
+	return ngx_http_vod_hls_get_default_id3_data(submodule_context, &conf->id3_data);
+}
+
 static ngx_int_t
 ngx_http_vod_hls_handle_master_playlist(
 	ngx_http_vod_submodule_context_t* submodule_context,
@@ -407,6 +508,7 @@ ngx_http_vod_hls_handle_iframe_playlist(
 	ngx_str_t* content_type)
 {
 	ngx_http_vod_loc_conf_t* conf = submodule_context->conf;
+	hls_mpegts_muxer_conf_t muxer_conf;
 	ngx_str_t base_url = ngx_null_string;
 	vod_status_t rc;
 
@@ -442,10 +544,16 @@ ngx_http_vod_hls_handle_iframe_playlist(
 		return ngx_http_vod_status_to_ngx_error(submodule_context->r, VOD_BAD_REQUEST);
 	}
 
+	rc = ngx_http_vod_hls_init_muxer_conf(submodule_context, &muxer_conf);
+	if (rc != NGX_OK)
+	{
+		return rc;
+	}
+
 	rc = m3u8_builder_build_iframe_playlist(
 		&submodule_context->request_context,
 		&conf->hls.m3u8_config,
-		&conf->hls.mpegts_muxer_config,
+		&muxer_conf,
 		&base_url,
 		&submodule_context->media_set,
 		response);
@@ -500,6 +608,7 @@ ngx_http_vod_hls_init_ts_frame_processor(
 	ngx_str_t* content_type)
 {
 	hls_encryption_params_t encryption_params;
+	hls_mpegts_muxer_conf_t muxer_conf;
 	hls_muxer_state_t* state;
 	vod_status_t rc;
 	bool_t reuse_output_buffers;
@@ -528,9 +637,15 @@ ngx_http_vod_hls_init_ts_frame_processor(
 	reuse_output_buffers = FALSE;
 #endif // NGX_HAVE_OPENSSL_EVP
 
+	rc = ngx_http_vod_hls_init_muxer_conf(submodule_context, &muxer_conf);
+	if (rc != NGX_OK)
+	{
+		return rc;
+	}
+
 	rc = hls_muxer_init_segment(
 		&submodule_context->request_context,
-		&submodule_context->conf->hls.mpegts_muxer_config,
+		&muxer_conf,
 		&encryption_params,
 		submodule_context->request_params.segment_index,
 		&submodule_context->media_set,
@@ -996,10 +1111,10 @@ ngx_http_vod_hls_create_loc_conf(
 	conf->absolute_master_urls = NGX_CONF_UNSET;
 	conf->absolute_index_urls = NGX_CONF_UNSET;
 	conf->absolute_iframe_urls = NGX_CONF_UNSET;
-	conf->mpegts_muxer_config.interleave_frames = NGX_CONF_UNSET;
-	conf->mpegts_muxer_config.align_frames = NGX_CONF_UNSET;
-	conf->mpegts_muxer_config.output_id3_timestamps = NGX_CONF_UNSET;
-	conf->mpegts_muxer_config.align_pts = NGX_CONF_UNSET;
+	conf->interleave_frames = NGX_CONF_UNSET;
+	conf->align_frames = NGX_CONF_UNSET;
+	conf->align_pts = NGX_CONF_UNSET;
+	conf->output_id3_timestamps = NGX_CONF_UNSET;
 	conf->encryption_method = NGX_CONF_UNSET_UINT;
 	conf->m3u8_config.output_iframes_playlist = NGX_CONF_UNSET;
 	conf->m3u8_config.force_unmuxed_segments = NGX_CONF_UNSET;
@@ -1034,11 +1149,15 @@ ngx_http_vod_hls_merge_loc_conf(
 	ngx_conf_merge_value(conf->m3u8_config.force_unmuxed_segments, prev->m3u8_config.force_unmuxed_segments, 0);
 	ngx_conf_merge_uint_value(conf->m3u8_config.container_format, prev->m3u8_config.container_format, HLS_CONTAINER_AUTO);
 
-	ngx_conf_merge_value(conf->mpegts_muxer_config.interleave_frames, prev->mpegts_muxer_config.interleave_frames, 0);
-	ngx_conf_merge_value(conf->mpegts_muxer_config.align_frames, prev->mpegts_muxer_config.align_frames, 1);
-	ngx_conf_merge_value(conf->mpegts_muxer_config.output_id3_timestamps, prev->mpegts_muxer_config.output_id3_timestamps, 0);
-	ngx_conf_merge_value(conf->mpegts_muxer_config.align_pts, prev->mpegts_muxer_config.align_pts, 0);
-
+	ngx_conf_merge_value(conf->interleave_frames, prev->interleave_frames, 0);
+	ngx_conf_merge_value(conf->align_frames, prev->align_frames, 1);
+	ngx_conf_merge_value(conf->align_pts, prev->align_pts, 0);
+	ngx_conf_merge_value(conf->output_id3_timestamps, prev->output_id3_timestamps, 0);
+	if (conf->id3_data == NULL)
+	{
+		conf->id3_data = prev->id3_data;
+	}
+
 	ngx_conf_merge_uint_value(conf->encryption_method, prev->encryption_method, HLS_ENC_NONE);
 
 	m3u8_builder_init_config(

ngx_http_vod_hls_commands.h

@@ -111,28 +111,35 @@
 	NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1,
 	ngx_conf_set_flag_slot,
 	NGX_HTTP_LOC_CONF_OFFSET,
-	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, mpegts_muxer_config.interleave_frames),
+	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, interleave_frames),
 	NULL },
 
 	{ ngx_string("vod_hls_mpegts_align_frames"),
 	NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1,
 	ngx_conf_set_flag_slot,
 	NGX_HTTP_LOC_CONF_OFFSET,
-	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, mpegts_muxer_config.align_frames),
+	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, align_frames),
 	NULL },
 
 	{ ngx_string("vod_hls_mpegts_output_id3_timestamps"),
 	NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1,
 	ngx_conf_set_flag_slot,
 	NGX_HTTP_LOC_CONF_OFFSET,
-	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, mpegts_muxer_config.output_id3_timestamps),
+	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, output_id3_timestamps),
+	NULL },
+
+	{ ngx_string("vod_hls_mpegts_id3_data"),
+	NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1,
+	ngx_http_set_complex_value_slot,
+	NGX_HTTP_LOC_CONF_OFFSET,
+	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, id3_data),
 	NULL },
 
 	{ ngx_string("vod_hls_mpegts_align_pts"),
 	NGX_HTTP_MAIN_CONF | NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1,
 	ngx_conf_set_flag_slot,
 	NGX_HTTP_LOC_CONF_OFFSET,
-	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, mpegts_muxer_config.align_pts),
+	BASE_OFFSET + offsetof(ngx_http_vod_hls_loc_conf_t, align_pts),
 	NULL },
 
 	{ ngx_string("vod_hls_force_unmuxed_segments"),

ngx_http_vod_hls_conf.h

@@ -12,7 +12,11 @@ typedef struct
 	ngx_flag_t absolute_index_urls;
 	ngx_flag_t absolute_iframe_urls;
 	ngx_str_t master_file_name_prefix;
-	hls_mpegts_muxer_conf_t mpegts_muxer_config;
+	bool_t interleave_frames;
+	bool_t align_frames;
+	bool_t align_pts;
+	bool_t output_id3_timestamps;
+	ngx_http_complex_value_t* id3_data;
 	vod_uint_t encryption_method;
 	ngx_http_complex_value_t* encryption_key_uri;
 

ngx_http_vod_module.c

@@ -593,6 +593,47 @@ ngx_http_vod_set_notification_id_var(ngx_http_request_t *r, ngx_http_variable_va
 	return NGX_OK;
 }
 
+static ngx_int_t
+ngx_http_vod_set_segment_time_var(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data)
+{
+	ngx_http_vod_ctx_t* ctx;
+	media_set_t* media_set;
+	int64_t value;
+	u_char* p;
+
+	ctx = ngx_http_get_module_ctx(r, ngx_http_vod_module);
+	if (ctx == NULL)
+	{
+		v->not_found = 1;
+		return NGX_OK;
+	}
+
+	media_set = &ctx->submodule_context.media_set;
+	if (media_set->filtered_tracks >= media_set->filtered_tracks_end)
+	{
+		v->not_found = 1;
+		return NGX_OK;
+	}
+
+	p = ngx_pnalloc(r->pool, NGX_INT64_LEN);
+	if (p == NULL)
+	{
+		ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+			"ngx_http_vod_set_segment_time_var: ngx_pnalloc failed");
+		return NGX_ERROR;
+	}
+
+	value = media_set_get_segment_time_millis(media_set);
+
+	v->data = p;
+	v->len = ngx_sprintf(p, "%L", value) - p;
+	v->valid = 1;
+	v->no_cacheable = 1;
+	v->not_found = 0;
+
+	return NGX_OK;
+}
+
 static ngx_int_t
 ngx_http_vod_set_segment_duration_var(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data)
 {
@@ -688,6 +729,7 @@ static ngx_http_vod_variable_t ngx_http_vod_variables[] = {
 	DEFINE_VAR(dynamic_mapping),
 	DEFINE_VAR(request_params),
 	DEFINE_VAR(notification_id),
+	DEFINE_VAR(segment_time),
 	DEFINE_VAR(segment_duration),
 	{ ngx_string("vod_frames_bytes_read"), ngx_http_vod_set_uint32_var, offsetof(ngx_http_vod_ctx_t, frames_bytes_read) },
 };