Re: [FFmpeg-devel] [PATCH] avformat/mov: initial support for emsg box
On 4/20/2021 1:01 AM, Brad Hards wrote: This adds support for the EventMessage box, which is apparently described in ISO/IEC 23009-1:2019, and is used for KLV metadata per MISB ST 1910. See https://www.gwg.nga.mil/misb/docs/standards/ST1910.1.pdf Sect 6.2.1 --- libavformat/isom.h | 15 libavformat/mov.c | 61 ++ 2 files changed, 76 insertions(+) diff --git a/libavformat/isom.h b/libavformat/isom.h index 5a6d504090..8ea62e91f0 100644 --- a/libavformat/isom.h +++ b/libavformat/isom.h @@ -79,6 +79,18 @@ typedef struct MOVDref { int16_t nlvl_to, nlvl_from; } MOVDref; +typedef struct MOVEmsg { +uint8_t version; +uint32_t timescale; +uint32_t presentation_time_delta; ///< only valid for version 0 +uint64_t presentation_time; ///< only valid for version 1 +uint32_t event_duration; +uint32_t id; +char *scheme_id_uri; +char *value; +uint8_t *message_data; +} MOVEmsg; + typedef struct MOVAtom { uint32_t type; int64_t size; /* total size (excluding the size and type fields) */ @@ -297,6 +309,9 @@ typedef struct MOVContext { int32_t movie_display_matrix[3][3]; ///< display matrix from mvhd int have_read_mfra_size; uint32_t mfra_size; +// Event Messages from DASH specification, used in MISB ST 1910 +unsigned emsg_count; ///< Number of event messages +MOVEmsg *emsg_data; ///< Array of Event Messages You're not freeing this array anywhere. Same with each entry's message_data, scheme_id_uri and value. } MOVContext; int ff_mp4_read_descr_len(AVIOContext *pb); diff --git a/libavformat/mov.c b/libavformat/mov.c index 7805330bf9..22bf0b36ea 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -5318,6 +5318,66 @@ static int mov_read_elst(MOVContext *c, AVIOContext *pb, MOVAtom atom) return 0; } +static int mov_read_emsg(MOVContext *c, AVIOContext *pb, MOVAtom atom) +{ +int err; +uint32_t bytes_read_from_atom = 0; +size_t num_bytes_in_last_read; +MOVEmsg *emsg; + +if ((uint64_t)c->emsg_count+1 >= UINT_MAX / sizeof(*c->emsg_data)) +return AVERROR_INVALIDDATA; +if ((err = av_reallocp_array(&c->emsg_data, c->emsg_count + 1, If there can be several emsg atoms in a bitstream, it may be a better idea to use av_fast_realloc() instead. Also, no limit to their lifetime? Being events, one would expect they could be dropped after being handled. + sizeof(*c->emsg_data))) < 0) { +c->emsg_count = 0; +return err; +} +emsg = &c->emsg_data[c->emsg_count++]; + +emsg->version = avio_r8(pb); +bytes_read_from_atom += 1; +avio_rb24(pb); /* flags */ +bytes_read_from_atom += 3; +if (emsg->version == 0) { +emsg->scheme_id_uri = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->scheme_id_uri, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->scheme_id_uri, num_bytes_in_last_read); +emsg->value = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->value, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->value, num_bytes_in_last_read); +emsg->timescale = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->presentation_time_delta = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->event_duration = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->id = avio_rb32(pb); +bytes_read_from_atom += 4; +} else if (emsg->version == 1) { +emsg->timescale = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->presentation_time = avio_rb64(pb); +bytes_read_from_atom += 8; +emsg->event_duration = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->id = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->scheme_id_uri = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->scheme_id_uri, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->scheme_id_uri, num_bytes_in_last_read); +emsg->value = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->value, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; Use avio_tell() instead of keeping a byte count with this bytes_read_from_atom variable. As is this is pretty unreadable. +av_realloc(emsg->value, num_bytes_in_last_read); +} +emsg->message_data = av_malloc(atom.size - bytes_read_from_atom); +num_bytes_in_last_read = avio_read(pb, emsg->message_data, atom.size - bytes_read_from_atom); +return 0; You're not doing anything with these event messages. You're only storing them in an ever
[FFmpeg-devel] [PATCH] avformat/mov: initial support for emsg box
This adds support for the EventMessage box, which is apparently described in ISO/IEC 23009-1:2019, and is used for KLV metadata per MISB ST 1910. See https://www.gwg.nga.mil/misb/docs/standards/ST1910.1.pdf Sect 6.2.1 --- libavformat/isom.h | 15 libavformat/mov.c | 61 ++ 2 files changed, 76 insertions(+) diff --git a/libavformat/isom.h b/libavformat/isom.h index 5a6d504090..8ea62e91f0 100644 --- a/libavformat/isom.h +++ b/libavformat/isom.h @@ -79,6 +79,18 @@ typedef struct MOVDref { int16_t nlvl_to, nlvl_from; } MOVDref; +typedef struct MOVEmsg { +uint8_t version; +uint32_t timescale; +uint32_t presentation_time_delta; ///< only valid for version 0 +uint64_t presentation_time; ///< only valid for version 1 +uint32_t event_duration; +uint32_t id; +char *scheme_id_uri; +char *value; +uint8_t *message_data; +} MOVEmsg; + typedef struct MOVAtom { uint32_t type; int64_t size; /* total size (excluding the size and type fields) */ @@ -297,6 +309,9 @@ typedef struct MOVContext { int32_t movie_display_matrix[3][3]; ///< display matrix from mvhd int have_read_mfra_size; uint32_t mfra_size; +// Event Messages from DASH specification, used in MISB ST 1910 +unsigned emsg_count; ///< Number of event messages +MOVEmsg *emsg_data; ///< Array of Event Messages } MOVContext; int ff_mp4_read_descr_len(AVIOContext *pb); diff --git a/libavformat/mov.c b/libavformat/mov.c index 7805330bf9..22bf0b36ea 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -5318,6 +5318,66 @@ static int mov_read_elst(MOVContext *c, AVIOContext *pb, MOVAtom atom) return 0; } +static int mov_read_emsg(MOVContext *c, AVIOContext *pb, MOVAtom atom) +{ +int err; +uint32_t bytes_read_from_atom = 0; +size_t num_bytes_in_last_read; +MOVEmsg *emsg; + +if ((uint64_t)c->emsg_count+1 >= UINT_MAX / sizeof(*c->emsg_data)) +return AVERROR_INVALIDDATA; +if ((err = av_reallocp_array(&c->emsg_data, c->emsg_count + 1, + sizeof(*c->emsg_data))) < 0) { +c->emsg_count = 0; +return err; +} +emsg = &c->emsg_data[c->emsg_count++]; + +emsg->version = avio_r8(pb); +bytes_read_from_atom += 1; +avio_rb24(pb); /* flags */ +bytes_read_from_atom += 3; +if (emsg->version == 0) { +emsg->scheme_id_uri = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->scheme_id_uri, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->scheme_id_uri, num_bytes_in_last_read); +emsg->value = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->value, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->value, num_bytes_in_last_read); +emsg->timescale = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->presentation_time_delta = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->event_duration = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->id = avio_rb32(pb); +bytes_read_from_atom += 4; +} else if (emsg->version == 1) { +emsg->timescale = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->presentation_time = avio_rb64(pb); +bytes_read_from_atom += 8; +emsg->event_duration = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->id = avio_rb32(pb); +bytes_read_from_atom += 4; +emsg->scheme_id_uri = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->scheme_id_uri, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->scheme_id_uri, num_bytes_in_last_read); +emsg->value = av_malloc(atom.size + 1); +num_bytes_in_last_read = avio_get_str(pb, atom.size, emsg->value, pb->buffer_size + 1); +bytes_read_from_atom += num_bytes_in_last_read; +av_realloc(emsg->value, num_bytes_in_last_read); +} +emsg->message_data = av_malloc(atom.size - bytes_read_from_atom); +num_bytes_in_last_read = avio_read(pb, emsg->message_data, atom.size - bytes_read_from_atom); +return 0; +} + static int mov_read_tmcd(MOVContext *c, AVIOContext *pb, MOVAtom atom) { MOVStreamContext *sc; @@ -6895,6 +6955,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = { { MKTAG('d','r','e','f'), mov_read_dref }, { MKTAG('e','d','t','s'), mov_read_default }, { MKTAG('e','l','s','t'), mov_read_elst }, +{ MKTAG('e','m','s','g'), mov_read_emsg }, { MKTAG('e','n','d','a'), mov_read_enda }, { MKTAG('f','i','e','l'), mov_read_fiel }, { MKTAG('a','d','r','m'), mov_read_adrm }, -- 2.27.0 ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org htt