[FFmpeg-devel] [PATCH v2 2/2] avformat/flvenc: add option to read metadata from file
Gyan Doshi
ffmpeg at gyani.pro
Sat Feb 4 12:11:12 EET 2023
On 2023-02-03 09:04 pm, Andreas Rheinhardt wrote:
> Gyan Doshi:
>> Useful, in conjuntion with option meta_period, to vary metadata during
>> stream.
>>
>> File format is ffmetadata.
>> ---
>> configure | 2 +-
>> doc/muxers.texi | 3 +
>> libavformat/flvenc.c | 133 +++++++++++++++++++++++++++++++++----------
>> 3 files changed, 107 insertions(+), 31 deletions(-)
>>
>> diff --git a/configure b/configure
>> index 9d78a244a3..de371632c4 100755
>> --- a/configure
>> +++ b/configure
>> @@ -3433,7 +3433,7 @@ eac3_demuxer_select="ac3_parser"
>> f4v_muxer_select="mov_muxer"
>> fifo_muxer_deps="threads"
>> flac_demuxer_select="flac_parser"
>> -flv_muxer_select="aac_adtstoasc_bsf"
>> +flv_muxer_select="aac_adtstoasc_bsf ffmetadata_demuxer"
>> gxf_muxer_select="pcm_rechunk_bsf"
>> hds_muxer_select="flv_muxer"
>> hls_demuxer_select="adts_header ac3_parser"
>> diff --git a/doc/muxers.texi b/doc/muxers.texi
>> index 02ecddf186..000c92b2a7 100644
>> --- a/doc/muxers.texi
>> +++ b/doc/muxers.texi
>> @@ -555,6 +555,9 @@ With every video packet.
>> @end table
>> Note that metadata will always be re-emitted if a metadata update event is signalled.
>>
>> + at item meta_filename
>> +Specify a ffmetadata file from which to load metadata.
>> +
>> @end table
>>
>> @anchor{framecrc}
>> diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
>> index d1c7a493d1..1332b18b41 100644
>> --- a/libavformat/flvenc.c
>> +++ b/libavformat/flvenc.c
>> @@ -122,6 +122,10 @@ typedef struct FLVContext {
>> double framerate;
>> AVCodecParameters *data_par;
>>
>> + char *meta_filename;
>> + AVFormatContext *meta_ctx;
>> + AVDictionary *meta_dict;
>> +
>> int flags;
>> int meta_period;
>> } FLVContext;
>> @@ -277,6 +281,92 @@ static void put_amf_bool(AVIOContext *pb, int b)
>> avio_w8(pb, !!b);
>> }
>>
>> +static int read_metadata_from_file(AVFormatContext *s, unsigned int ts, int header)
>> +{
>> + FLVContext *flv = s->priv_data;
>> + const AVInputFormat *meta_format = NULL;
>> + AVDictionary *current_meta_dict = NULL;
>> + float timestamp = ts/1000.f;
>> + int ret;
>> +
>> + if (!flv->meta_filename)
>> + return 0;
>> +
>> + meta_format = av_find_input_format("ffmetadata");
>> + if (!meta_format) {
>> + av_log(s, AV_LOG_ERROR, "ffmetadata demuxer not found.\n");
>> + return AVERROR(ENOSYS);
>> + }
>> +
>> + avformat_close_input(&flv->meta_ctx);
>> +
>> + ret = avformat_open_input(&flv->meta_ctx, flv->meta_filename, meta_format, NULL);
>> + if (ret < 0) {
>> + av_log(s, AV_LOG_ERROR, "Failed to read metadata from file %s t: %f.", flv->meta_filename, timestamp);
>> + if (flv->meta_dict)
>> + av_log(s, AV_LOG_ERROR, " Continuing with old metadata.");
>> + av_log(s, AV_LOG_ERROR, "\n");
>> + return ret;
>> + }
>> +
>> + if (flv->meta_dict) {
>> + av_dict_copy(¤t_meta_dict, flv->meta_dict, 0);
>> + av_dict_free(&flv->meta_dict);
>> + }
>> +
>> + ret = av_dict_copy(&flv->meta_dict, flv->meta_ctx->metadata, 0);
>> + if (ret < 0) {
>> + av_log(s, AV_LOG_ERROR, "Could not transfer metadata from %s at %f seconds. Continuing with old metadata.\n", flv->meta_filename, timestamp);
>> + av_dict_free(&flv->meta_dict);
>> + av_dict_copy(&flv->meta_dict, current_meta_dict, 0);
>> + av_dict_free(¤t_meta_dict);
>> + return ret;
>> + }
>> +
>> + av_log(s, AV_LOG_VERBOSE, "Metadata from file %s updated %s at %f seconds.\n", flv->meta_filename, header ? "in header" : "in video packet", timestamp);
>> + av_dict_free(¤t_meta_dict);
>> + avformat_close_input(&flv->meta_ctx);
>> +
>> + return 0;
>> +}
>> +
>> +static int write_user_metadata_tag(AVFormatContext *s, AVDictionaryEntry *tag, AVIOContext *pb, int *metadata_count)
>> +{
>> +
>> + av_log(s, AV_LOG_DEBUG, "Writing tag %s with value %s count: %d\n", tag->key, tag->value, *metadata_count);
>> +
>> + if( !strcmp(tag->key, "width")
>> + ||!strcmp(tag->key, "height")
>> + ||!strcmp(tag->key, "videodatarate")
>> + ||!strcmp(tag->key, "framerate")
>> + ||!strcmp(tag->key, "videocodecid")
>> + ||!strcmp(tag->key, "audiodatarate")
>> + ||!strcmp(tag->key, "audiosamplerate")
>> + ||!strcmp(tag->key, "audiosamplesize")
>> + ||!strcmp(tag->key, "stereo")
>> + ||!strcmp(tag->key, "audiocodecid")
>> + ||!strcmp(tag->key, "duration")
>> + ||!strcmp(tag->key, "onMetaData")
>> + ||!strcmp(tag->key, "datasize")
>> + ||!strcmp(tag->key, "lasttimestamp")
>> + ||!strcmp(tag->key, "totalframes")
>> + ||!strcmp(tag->key, "hasAudio")
>> + ||!strcmp(tag->key, "hasVideo")
>> + ||!strcmp(tag->key, "hasCuePoints")
>> + ||!strcmp(tag->key, "hasMetadata")
>> + ||!strcmp(tag->key, "hasKeyframes")
>> + ){
>> + av_log(s, AV_LOG_DEBUG, "Ignoring metadata for %s\n", tag->key);
>> + return AVERROR(EINVAL);
>> + }
>> + put_amf_string(pb, tag->key);
>> + avio_w8(pb, AMF_DATA_TYPE_STRING);
>> + put_amf_string(pb, tag->value);
>> + (*metadata_count)++;
>> +
>> + return 0;
>> +}
>> +
>> static void write_metadata(AVFormatContext *s, unsigned int ts)
>> {
>> AVIOContext *pb = s->pb;
>> @@ -360,36 +450,11 @@ static void write_metadata(AVFormatContext *s, unsigned int ts)
>> }
>>
>> ff_standardize_creation_time(s);
>> - while ((tag = av_dict_iterate(s->metadata, tag))) {
>> - if( !strcmp(tag->key, "width")
>> - ||!strcmp(tag->key, "height")
>> - ||!strcmp(tag->key, "videodatarate")
>> - ||!strcmp(tag->key, "framerate")
>> - ||!strcmp(tag->key, "videocodecid")
>> - ||!strcmp(tag->key, "audiodatarate")
>> - ||!strcmp(tag->key, "audiosamplerate")
>> - ||!strcmp(tag->key, "audiosamplesize")
>> - ||!strcmp(tag->key, "stereo")
>> - ||!strcmp(tag->key, "audiocodecid")
>> - ||!strcmp(tag->key, "duration")
>> - ||!strcmp(tag->key, "onMetaData")
>> - ||!strcmp(tag->key, "datasize")
>> - ||!strcmp(tag->key, "lasttimestamp")
>> - ||!strcmp(tag->key, "totalframes")
>> - ||!strcmp(tag->key, "hasAudio")
>> - ||!strcmp(tag->key, "hasVideo")
>> - ||!strcmp(tag->key, "hasCuePoints")
>> - ||!strcmp(tag->key, "hasMetadata")
>> - ||!strcmp(tag->key, "hasKeyframes")
>> - ){
>> - av_log(s, AV_LOG_DEBUG, "Ignoring metadata for %s\n", tag->key);
>> - continue;
>> - }
>> - put_amf_string(pb, tag->key);
>> - avio_w8(pb, AMF_DATA_TYPE_STRING);
>> - put_amf_string(pb, tag->value);
>> - metadata_count++;
>> - }
>> +
>> + while (tag = av_dict_get(s->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))
>> + write_user_metadata_tag(s, tag, pb, &metadata_count);
>> + while (tag = av_dict_get(flv->meta_dict, "", tag, AV_DICT_IGNORE_SUFFIX))
>> + write_user_metadata_tag(s, tag, pb, &metadata_count);
>>
>> if (write_duration_filesize) {
>> put_amf_string(pb, "filesize");
>> @@ -718,6 +783,7 @@ static int flv_write_header(AVFormatContext *s)
>> if (flv->flags & FLV_NO_METADATA) {
>> pb->seekable = 0;
>> } else {
>> + read_metadata_from_file(s, 0, 1);
>> write_metadata(s, 0);
>> }
>>
>> @@ -880,6 +946,7 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
>> if (meta_upd_flag ||
>> (flv->meta_period == FLV_META_AT_KF && par->codec_type == AVMEDIA_TYPE_VIDEO && (pkt->flags & AV_PKT_FLAG_KEY)) ||
>> (flv->meta_period == FLV_META_EVERY_PACKET && par->codec_type == AVMEDIA_TYPE_VIDEO )) {
>> + read_metadata_from_file(s, ts, 0);
>> write_metadata(s, ts);
>> if (meta_upd_flag)
>> s->event_flags &= ~AVSTREAM_EVENT_FLAG_METADATA_UPDATED;
>> @@ -1053,6 +1120,11 @@ static void flv_deinit(AVFormatContext *s)
>> }
>> flv->filepositions = flv->head_filepositions = NULL;
>> flv->filepositions_count = 0;
>> +
>> + if (flv->meta_dict)
>> + av_dict_free(&flv->meta_dict);
>> +
>> + avformat_close_input(&flv->meta_ctx);
>> }
>>
>> static const AVOption options[] = {
>> @@ -1066,6 +1138,7 @@ static const AVOption options[] = {
>> { "at_start", "only once at start", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_META_ONCE_AT_START}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "meta_period" },
>> { "at_keyframes", "with every video keyframe", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_META_AT_KF}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "meta_period" },
>> { "every_packet", "with every video packet", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_META_EVERY_PACKET}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "meta_period" },
>> + { "meta_filename", "ffmetadata file to import metadata", offsetof(FLVContext, meta_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
>> { NULL },
>> };
>>
> What does this achieve that can't be achieved by other means (namely by
> an API-user updating the relevant metadata dictionaries)?
This option together with meta_period is for CLI users. Similar to
drawtext's textfile + reload.
It's been used in production for over a year at a client. Think it will
be broadly useful.
Regards,
Gyan
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