Message ID | 1648423513-21261-1-git-send-email-lance.lmwang@gmail.com |
---|---|
State | New |
Headers | show |
Series | [FFmpeg-devel,1/4] avutil: add ambient viewing environment metadata side data | expand |
Context | Check | Description |
---|---|---|
andriy/make_x86 | success | Make finished |
andriy/make_fate_x86 | success | Make fate finished |
On 3/27/2022 8:25 PM, lance.lmwang@gmail.com wrote: > From: Limin Wang <lance.lmwang@gmail.com> > > Signed-off-by: Limin Wang <lance.lmwang@gmail.com> > --- > libavutil/Makefile | 2 + > libavutil/ambient_viewing_env_metadata.c | 47 +++++++++++++++++++++ > libavutil/ambient_viewing_env_metadata.h | 72 ++++++++++++++++++++++++++++++++ > libavutil/frame.c | 1 + > libavutil/frame.h | 6 +++ > 5 files changed, 128 insertions(+) > create mode 100644 libavutil/ambient_viewing_env_metadata.c > create mode 100644 libavutil/ambient_viewing_env_metadata.h > > diff --git a/libavutil/Makefile b/libavutil/Makefile > index 81df3b0..e388d33 100644 > --- a/libavutil/Makefile > +++ b/libavutil/Makefile > @@ -26,6 +26,7 @@ HEADERS = adler32.h \ > display.h \ > dovi_meta.h \ > downmix_info.h \ > + ambient_viewing_env_metadata.h \ > encryption_info.h \ > error.h \ > eval.h \ > @@ -119,6 +120,7 @@ OBJS = adler32.o \ > display.o \ > dovi_meta.o \ > downmix_info.o \ > + ambient_viewing_env_metadata.o \ > encryption_info.o \ > error.o \ > eval.o \ > diff --git a/libavutil/ambient_viewing_env_metadata.c b/libavutil/ambient_viewing_env_metadata.c > new file mode 100644 > index 0000000..7006b64 > --- /dev/null > +++ b/libavutil/ambient_viewing_env_metadata.c > @@ -0,0 +1,47 @@ > +/** > + * Copyright (c) 2022 Limin Wang <lance.lmwang@gmail.com> > + * > + * This file is part of FFmpeg. > + * > + * FFmpeg is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * FFmpeg is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with FFmpeg; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA > + */ > + > +#include <stdint.h> > +#include <string.h> > +#include "ambient_viewing_env_metadata.h" > +#include "mem.h" > + > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size) > +{ > + AVAmbientViewingEnvMetadata *metadata = av_mallocz(sizeof(*metadata)); > + > + if (size) > + *size = sizeof(*metadata); > + > + return metadata; > +} > + > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame) > +{ > + AVFrameSideData *side_data = av_frame_new_side_data(frame, > + AV_FRAME_DATA_AMBIENT_VIEWING_ENV, > + sizeof(AVAmbientViewingEnvMetadata)); > + if (!side_data) > + return NULL; > + > + memset(side_data->data, 0, sizeof(AVAmbientViewingEnvMetadata)); > + > + return (AVAmbientViewingEnvMetadata *)side_data->data; > +} > diff --git a/libavutil/ambient_viewing_env_metadata.h b/libavutil/ambient_viewing_env_metadata.h > new file mode 100644 > index 0000000..b0fbcd0 > --- /dev/null > +++ b/libavutil/ambient_viewing_env_metadata.h > @@ -0,0 +1,72 @@ > +/* > + * Copyright (c) 2022 Limin Wang <lance.lmwang@gmail.com> > + * > + * This file is part of FFmpeg. > + * > + * FFmpeg is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * FFmpeg is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with FFmpeg; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA > + */ > + > +#ifndef AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H > +#define AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H > + > +#include "frame.h" > + > + > +/** > + * The characteristics of the nominal ambient viewing environment for > + * the display of the associated video content. > + * To be used as payload of a AVFrameSideData the appropriate type. > + * > + * @note The struct should be allocated with av_ambient_viewing_env_metadata_alloc() > + * and its size is not a part of the public ABI. > + */ > +typedef struct AVAmbientViewingEnvMetadata { > + /** > + * specifies the environmental illuminance of the ambient viewing > + * environment in units of 0.0001 lux. > + * ambient_illuminance shall not be equal to 0. > + */ > + uint32_t ambient_illuminance; > + /** > + * specify the normalized x and y chromaticity coordinates, respectively, > + * of the environmental ambient light in the nominal viewing environment, > + * according to the CIE 1931 definition of x and y as specified in ISO > + * 11664-1 (see also ISO 11664-3 and CIE 15), in normalized increments of > + * 0.00002. The values of ambient_light_x and ambient_light_y shall be in > + * the range of 0 to 50 000 > + */ > + uint16_t ambient_light_x; > + uint16_t ambient_light_y; > +} AVAmbientViewingEnvMetadata; We don't need a new header for this. Just add it to mastering_display_metadata.h. The other structs there are based on other entries from the same spec (H.274) and have similar purposes. > + > +/** > + * Allocate an AVAmbientViewingEnvMetadata structure and set its fields to > + * default values. The resulting struct can be freed using av_freep(). > + * > + * @return An AVAmbientViewingEnvMetadata filled with default values or NULL > + * on failure. > + */ > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size); > + > +/** > + * Allocate a complete AVAmbientViewingEnvMetadata and add it to the frame. > + * > + * @param frame The frame which side data is added to. > + * > + * @return The AVAmbientViewingEnvMetadata structure to be filled by caller. > + */ > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame); > + > +#endif /* AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H */ > diff --git a/libavutil/frame.c b/libavutil/frame.c > index fbb869f..8882da2 100644 > --- a/libavutil/frame.c > +++ b/libavutil/frame.c > @@ -815,6 +815,7 @@ const char *av_frame_side_data_name(enum AVFrameSideDataType type) > case AV_FRAME_DATA_DETECTION_BBOXES: return "Bounding boxes for object detection and classification"; > case AV_FRAME_DATA_DOVI_RPU_BUFFER: return "Dolby Vision RPU Data"; > case AV_FRAME_DATA_DOVI_METADATA: return "Dolby Vision Metadata"; > + case AV_FRAME_DATA_AMBIENT_VIEWING_ENV: return "Ambient Viewing Environment"; > } > return NULL; > } > diff --git a/libavutil/frame.h b/libavutil/frame.h > index 33fac20..f7b1d4e 100644 > --- a/libavutil/frame.h > +++ b/libavutil/frame.h > @@ -209,6 +209,12 @@ enum AVFrameSideDataType { > * volume transform - CUVA 005.1-2021. > */ > AV_FRAME_DATA_DYNAMIC_HDR_VIVID, > + > + /** > + * ambient viewing environment for a video frame, as described by > + * the AVAmbientViewingEnvMetadata. > + */ > + AV_FRAME_DATA_AMBIENT_VIEWING_ENV, > }; > > enum AVActiveFormatDescription {
On Sun, Mar 27, 2022 at 08:30:30PM -0300, James Almer wrote: > > > On 3/27/2022 8:25 PM, lance.lmwang@gmail.com wrote: > > From: Limin Wang <lance.lmwang@gmail.com> > > > > Signed-off-by: Limin Wang <lance.lmwang@gmail.com> > > --- > > libavutil/Makefile | 2 + > > libavutil/ambient_viewing_env_metadata.c | 47 +++++++++++++++++++++ > > libavutil/ambient_viewing_env_metadata.h | 72 ++++++++++++++++++++++++++++++++ > > libavutil/frame.c | 1 + > > libavutil/frame.h | 6 +++ > > 5 files changed, 128 insertions(+) > > create mode 100644 libavutil/ambient_viewing_env_metadata.c > > create mode 100644 libavutil/ambient_viewing_env_metadata.h > > > > diff --git a/libavutil/Makefile b/libavutil/Makefile > > index 81df3b0..e388d33 100644 > > --- a/libavutil/Makefile > > +++ b/libavutil/Makefile > > @@ -26,6 +26,7 @@ HEADERS = adler32.h \ > > display.h \ > > dovi_meta.h \ > > downmix_info.h \ > > + ambient_viewing_env_metadata.h \ > > encryption_info.h \ > > error.h \ > > eval.h \ > > @@ -119,6 +120,7 @@ OBJS = adler32.o \ > > display.o \ > > dovi_meta.o \ > > downmix_info.o \ > > + ambient_viewing_env_metadata.o \ > > encryption_info.o \ > > error.o \ > > eval.o \ > > diff --git a/libavutil/ambient_viewing_env_metadata.c b/libavutil/ambient_viewing_env_metadata.c > > new file mode 100644 > > index 0000000..7006b64 > > --- /dev/null > > +++ b/libavutil/ambient_viewing_env_metadata.c > > @@ -0,0 +1,47 @@ > > +/** > > + * Copyright (c) 2022 Limin Wang <lance.lmwang@gmail.com> > > + * > > + * This file is part of FFmpeg. > > + * > > + * FFmpeg is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU Lesser General Public > > + * License as published by the Free Software Foundation; either > > + * version 2.1 of the License, or (at your option) any later version. > > + * > > + * FFmpeg is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + * Lesser General Public License for more details. > > + * > > + * You should have received a copy of the GNU Lesser General Public > > + * License along with FFmpeg; if not, write to the Free Software > > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA > > + */ > > + > > +#include <stdint.h> > > +#include <string.h> > > +#include "ambient_viewing_env_metadata.h" > > +#include "mem.h" > > + > > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size) > > +{ > > + AVAmbientViewingEnvMetadata *metadata = av_mallocz(sizeof(*metadata)); > > + > > + if (size) > > + *size = sizeof(*metadata); > > + > > + return metadata; > > +} > > + > > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame) > > +{ > > + AVFrameSideData *side_data = av_frame_new_side_data(frame, > > + AV_FRAME_DATA_AMBIENT_VIEWING_ENV, > > + sizeof(AVAmbientViewingEnvMetadata)); > > + if (!side_data) > > + return NULL; > > + > > + memset(side_data->data, 0, sizeof(AVAmbientViewingEnvMetadata)); > > + > > + return (AVAmbientViewingEnvMetadata *)side_data->data; > > +} > > diff --git a/libavutil/ambient_viewing_env_metadata.h b/libavutil/ambient_viewing_env_metadata.h > > new file mode 100644 > > index 0000000..b0fbcd0 > > --- /dev/null > > +++ b/libavutil/ambient_viewing_env_metadata.h > > @@ -0,0 +1,72 @@ > > +/* > > + * Copyright (c) 2022 Limin Wang <lance.lmwang@gmail.com> > > + * > > + * This file is part of FFmpeg. > > + * > > + * FFmpeg is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU Lesser General Public > > + * License as published by the Free Software Foundation; either > > + * version 2.1 of the License, or (at your option) any later version. > > + * > > + * FFmpeg is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + * Lesser General Public License for more details. > > + * > > + * You should have received a copy of the GNU Lesser General Public > > + * License along with FFmpeg; if not, write to the Free Software > > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA > > + */ > > + > > +#ifndef AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H > > +#define AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H > > + > > +#include "frame.h" > > + > > + > > +/** > > + * The characteristics of the nominal ambient viewing environment for > > + * the display of the associated video content. > > + * To be used as payload of a AVFrameSideData the appropriate type. > > + * > > + * @note The struct should be allocated with av_ambient_viewing_env_metadata_alloc() > > + * and its size is not a part of the public ABI. > > + */ > > +typedef struct AVAmbientViewingEnvMetadata { > > + /** > > + * specifies the environmental illuminance of the ambient viewing > > + * environment in units of 0.0001 lux. > > + * ambient_illuminance shall not be equal to 0. > > + */ > > + uint32_t ambient_illuminance; > > + /** > > + * specify the normalized x and y chromaticity coordinates, respectively, > > + * of the environmental ambient light in the nominal viewing environment, > > + * according to the CIE 1931 definition of x and y as specified in ISO > > + * 11664-1 (see also ISO 11664-3 and CIE 15), in normalized increments of > > + * 0.00002. The values of ambient_light_x and ambient_light_y shall be in > > + * the range of 0 to 50 000 > > + */ > > + uint16_t ambient_light_x; > > + uint16_t ambient_light_y; > > +} AVAmbientViewingEnvMetadata; > > We don't need a new header for this. Just add it to > mastering_display_metadata.h. The other structs there are based on other > entries from the same spec (H.274) and have similar purposes. OK, will move to there as suggestion. > > > + > > +/** > > + * Allocate an AVAmbientViewingEnvMetadata structure and set its fields to > > + * default values. The resulting struct can be freed using av_freep(). > > + * > > + * @return An AVAmbientViewingEnvMetadata filled with default values or NULL > > + * on failure. > > + */ > > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size); > > + > > +/** > > + * Allocate a complete AVAmbientViewingEnvMetadata and add it to the frame. > > + * > > + * @param frame The frame which side data is added to. > > + * > > + * @return The AVAmbientViewingEnvMetadata structure to be filled by caller. > > + */ > > +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame); > > + > > +#endif /* AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H */ > > diff --git a/libavutil/frame.c b/libavutil/frame.c > > index fbb869f..8882da2 100644 > > --- a/libavutil/frame.c > > +++ b/libavutil/frame.c > > @@ -815,6 +815,7 @@ const char *av_frame_side_data_name(enum AVFrameSideDataType type) > > case AV_FRAME_DATA_DETECTION_BBOXES: return "Bounding boxes for object detection and classification"; > > case AV_FRAME_DATA_DOVI_RPU_BUFFER: return "Dolby Vision RPU Data"; > > case AV_FRAME_DATA_DOVI_METADATA: return "Dolby Vision Metadata"; > > + case AV_FRAME_DATA_AMBIENT_VIEWING_ENV: return "Ambient Viewing Environment"; > > } > > return NULL; > > } > > diff --git a/libavutil/frame.h b/libavutil/frame.h > > index 33fac20..f7b1d4e 100644 > > --- a/libavutil/frame.h > > +++ b/libavutil/frame.h > > @@ -209,6 +209,12 @@ enum AVFrameSideDataType { > > * volume transform - CUVA 005.1-2021. > > */ > > AV_FRAME_DATA_DYNAMIC_HDR_VIVID, > > + > > + /** > > + * ambient viewing environment for a video frame, as described by > > + * the AVAmbientViewingEnvMetadata. > > + */ > > + AV_FRAME_DATA_AMBIENT_VIEWING_ENV, > > }; > > enum AVActiveFormatDescription { > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
diff --git a/libavutil/Makefile b/libavutil/Makefile index 81df3b0..e388d33 100644 --- a/libavutil/Makefile +++ b/libavutil/Makefile @@ -26,6 +26,7 @@ HEADERS = adler32.h \ display.h \ dovi_meta.h \ downmix_info.h \ + ambient_viewing_env_metadata.h \ encryption_info.h \ error.h \ eval.h \ @@ -119,6 +120,7 @@ OBJS = adler32.o \ display.o \ dovi_meta.o \ downmix_info.o \ + ambient_viewing_env_metadata.o \ encryption_info.o \ error.o \ eval.o \ diff --git a/libavutil/ambient_viewing_env_metadata.c b/libavutil/ambient_viewing_env_metadata.c new file mode 100644 index 0000000..7006b64 --- /dev/null +++ b/libavutil/ambient_viewing_env_metadata.c @@ -0,0 +1,47 @@ +/** + * Copyright (c) 2022 Limin Wang <lance.lmwang@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <stdint.h> +#include <string.h> +#include "ambient_viewing_env_metadata.h" +#include "mem.h" + +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size) +{ + AVAmbientViewingEnvMetadata *metadata = av_mallocz(sizeof(*metadata)); + + if (size) + *size = sizeof(*metadata); + + return metadata; +} + +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame) +{ + AVFrameSideData *side_data = av_frame_new_side_data(frame, + AV_FRAME_DATA_AMBIENT_VIEWING_ENV, + sizeof(AVAmbientViewingEnvMetadata)); + if (!side_data) + return NULL; + + memset(side_data->data, 0, sizeof(AVAmbientViewingEnvMetadata)); + + return (AVAmbientViewingEnvMetadata *)side_data->data; +} diff --git a/libavutil/ambient_viewing_env_metadata.h b/libavutil/ambient_viewing_env_metadata.h new file mode 100644 index 0000000..b0fbcd0 --- /dev/null +++ b/libavutil/ambient_viewing_env_metadata.h @@ -0,0 +1,72 @@ +/* + * Copyright (c) 2022 Limin Wang <lance.lmwang@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H +#define AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H + +#include "frame.h" + + +/** + * The characteristics of the nominal ambient viewing environment for + * the display of the associated video content. + * To be used as payload of a AVFrameSideData the appropriate type. + * + * @note The struct should be allocated with av_ambient_viewing_env_metadata_alloc() + * and its size is not a part of the public ABI. + */ +typedef struct AVAmbientViewingEnvMetadata { + /** + * specifies the environmental illuminance of the ambient viewing + * environment in units of 0.0001 lux. + * ambient_illuminance shall not be equal to 0. + */ + uint32_t ambient_illuminance; + /** + * specify the normalized x and y chromaticity coordinates, respectively, + * of the environmental ambient light in the nominal viewing environment, + * according to the CIE 1931 definition of x and y as specified in ISO + * 11664-1 (see also ISO 11664-3 and CIE 15), in normalized increments of + * 0.00002. The values of ambient_light_x and ambient_light_y shall be in + * the range of 0 to 50 000 + */ + uint16_t ambient_light_x; + uint16_t ambient_light_y; +} AVAmbientViewingEnvMetadata; + +/** + * Allocate an AVAmbientViewingEnvMetadata structure and set its fields to + * default values. The resulting struct can be freed using av_freep(). + * + * @return An AVAmbientViewingEnvMetadata filled with default values or NULL + * on failure. + */ +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size); + +/** + * Allocate a complete AVAmbientViewingEnvMetadata and add it to the frame. + * + * @param frame The frame which side data is added to. + * + * @return The AVAmbientViewingEnvMetadata structure to be filled by caller. + */ +AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame); + +#endif /* AVUTIL_AMBIENT_VIEWING_ENV_METADATA_H */ diff --git a/libavutil/frame.c b/libavutil/frame.c index fbb869f..8882da2 100644 --- a/libavutil/frame.c +++ b/libavutil/frame.c @@ -815,6 +815,7 @@ const char *av_frame_side_data_name(enum AVFrameSideDataType type) case AV_FRAME_DATA_DETECTION_BBOXES: return "Bounding boxes for object detection and classification"; case AV_FRAME_DATA_DOVI_RPU_BUFFER: return "Dolby Vision RPU Data"; case AV_FRAME_DATA_DOVI_METADATA: return "Dolby Vision Metadata"; + case AV_FRAME_DATA_AMBIENT_VIEWING_ENV: return "Ambient Viewing Environment"; } return NULL; } diff --git a/libavutil/frame.h b/libavutil/frame.h index 33fac20..f7b1d4e 100644 --- a/libavutil/frame.h +++ b/libavutil/frame.h @@ -209,6 +209,12 @@ enum AVFrameSideDataType { * volume transform - CUVA 005.1-2021. */ AV_FRAME_DATA_DYNAMIC_HDR_VIVID, + + /** + * ambient viewing environment for a video frame, as described by + * the AVAmbientViewingEnvMetadata. + */ + AV_FRAME_DATA_AMBIENT_VIEWING_ENV, }; enum AVActiveFormatDescription {