[FFmpeg-devel] [PATCH v1] avformat/flvenc: add add_keyframe_index option
Steven Liu
lingjiujianke at gmail.com
Fri Nov 4 14:58:56 EET 2016
2016-11-04 20:44 GMT+08:00 Michael Niedermayer <michael at niedermayer.cc>:
> On Fri, Nov 04, 2016 at 11:24:06AM +0800, Steven Liu wrote:
> > Add keyframe index metadata
> > Used to facilitate seeking; particularly for HTTP pseudo streaming.
> >
> > Reviewed-by: Lou Logan <lou at lrcd.com>
> > Signed-off-by: Steven Liu <liuqi at gosun.com>
> > ---
> > doc/muxers.texi | 3 +
> > libavformat/flvenc.c | 331 ++++++++++++++++++++++++++++++
> ++++++++++++++++++--
> > 2 files changed, 324 insertions(+), 10 deletions(-)
> >
> > diff --git a/doc/muxers.texi b/doc/muxers.texi
> > index 488ed43..806182a 100644
> > --- a/doc/muxers.texi
> > +++ b/doc/muxers.texi
> > @@ -147,6 +147,9 @@ Place AAC sequence header based on audio stream data.
> >
> > @item no_sequence_end
> > Disable sequence end tag.
> > +
> > + at item add_keyframe_index
> > +Used to facilitate seeking; particularly for HTTP pseudo streaming.
> > @end table
> > @end table
> >
> > diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
> > index e50f8e4..ee06a92 100644
> > --- a/libavformat/flvenc.c
> > +++ b/libavformat/flvenc.c
> > @@ -24,6 +24,8 @@
> > #include "libavutil/intfloat.h"
> > #include "libavutil/avassert.h"
> > #include "libavutil/mathematics.h"
> > +#include "avio_internal.h"
> > +#include "avio.h"
> > #include "avc.h"
> > #include "avformat.h"
> > #include "flv.h"
> > @@ -64,8 +66,15 @@ static const AVCodecTag flv_audio_codec_ids[] = {
> > typedef enum {
> > FLV_AAC_SEQ_HEADER_DETECT = (1 << 0),
> > FLV_NO_SEQUENCE_END = (1 << 1),
> > + FLV_ADD_KEYFRAME_INDEX = (1 << 2),
> > } FLVFlags;
> >
> > +typedef struct FLVFileposition {
> > + int64_t keyframe_position;
> > + double keyframe_timestamp;
> > + struct FLVFileposition *next;
> > +} FLVFileposition;
> > +
> > typedef struct FLVContext {
> > AVClass *av_class;
> > int reserved;
> > @@ -74,6 +83,33 @@ typedef struct FLVContext {
> > int64_t duration;
> > int64_t delay; ///< first dts delay (needed for AVC & Speex)
> >
> > + int64_t datastart_offset;
> > + int64_t datasize_offset;
> > + int64_t datasize;
> > + int64_t videosize_offset;
> > + int64_t videosize;
> > + int64_t audiosize_offset;
> > + int64_t audiosize;
> > +
> > + int64_t metadata_size_pos;
> > + int64_t metadata_totalsize_pos;
> > + int64_t metadata_totalsize;
> > + int64_t keyframe_index_size;
> > +
> > + int64_t lasttimestamp_offset;
> > + double lasttimestamp;
> > + int64_t lastkeyframetimestamp_offset;
> > + double lastkeyframetimestamp;
> > + int64_t lastkeyframelocation_offset;
> > + int64_t lastkeyframelocation;
> > +
> > + int acurframeindex;
> > + int64_t keyframes_info_offset;
> > +
> > + int64_t filepositions_count;
> > + FLVFileposition *filepositions;
> > + FLVFileposition *head_filepositions;
> > +
> > AVCodecParameters *audio_par;
> > AVCodecParameters *video_par;
> > double framerate;
> > @@ -202,6 +238,17 @@ static void put_amf_double(AVIOContext *pb, double
> d)
> > avio_wb64(pb, av_double2int(d));
> > }
> >
> > +static void put_amf_byte(AVIOContext *pb, unsigned char abyte)
> > +{
> > + avio_w8(pb, abyte);
> > +}
> > +
> > +static void put_amf_dword_array(AVIOContext *pb, uint32_t dw)
> > +{
> > + avio_w8(pb, AMF_DATA_TYPE_ARRAY);
> > + avio_wb32(pb, dw);
> > +}
> > +
> > static void put_amf_bool(AVIOContext *pb, int b)
> > {
> > avio_w8(pb, AMF_DATA_TYPE_BOOL);
> > @@ -213,12 +260,12 @@ static void write_metadata(AVFormatContext *s,
> unsigned int ts)
> > AVIOContext *pb = s->pb;
> > FLVContext *flv = s->priv_data;
> > int metadata_count = 0;
> > - int64_t metadata_size_pos, data_size, metadata_count_pos;
> > + int64_t metadata_count_pos;
> > AVDictionaryEntry *tag = NULL;
> >
> > /* write meta_tag */
> > - avio_w8(pb, 18); // tag type META
> > - metadata_size_pos = avio_tell(pb);
> > + avio_w8(pb, FLV_TAG_TYPE_META); // tag type META
> > + flv->metadata_size_pos = avio_tell(pb);
> > avio_wb24(pb, 0); // size of data part (sum of all parts
> below)
> > avio_wb24(pb, ts); // timestamp
> > avio_wb32(pb, 0); // reserved
> > @@ -327,19 +374,87 @@ static void write_metadata(AVFormatContext *s,
> unsigned int ts)
> > put_amf_double(pb, 0); // delayed write
> > }
> >
> > + if (flv->flags & FLV_ADD_KEYFRAME_INDEX) {
> > + flv->acurframeindex = 0;
> > + flv->keyframe_index_size = 0;
> > +
> > + put_amf_string(pb, "hasVideo");
> > + put_amf_bool(pb, !!flv->video_par);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "hasKeyframes");
> > + put_amf_bool(pb, 1);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "hasAudio");
> > + put_amf_bool(pb, !!flv->audio_par);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "hasMetadata");
> > + put_amf_bool(pb, 1);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "canSeekToEnd");
> > + put_amf_bool(pb, 1);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "datasize");
> > + flv->datasize_offset = avio_tell(pb);
> > + flv->datasize = 0;
> > + put_amf_double(pb, flv->datasize);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "videosize");
> > + flv->videosize_offset = avio_tell(pb);
> > + flv->videosize = 0;
> > + put_amf_double(pb, flv->videosize);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "audiosize");
> > + flv->audiosize_offset = avio_tell(pb);
> > + flv->audiosize = 0;
> > + put_amf_double(pb, flv->audiosize);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "lasttimestamp");
> > + flv->lasttimestamp_offset = avio_tell(pb);
> > + flv->lasttimestamp = 0;
> > + put_amf_double(pb, 0);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "lastkeyframetimestamp");
> > + flv->lastkeyframetimestamp_offset = avio_tell(pb);
> > + flv->lastkeyframetimestamp = 0;
> > + put_amf_double(pb, 0);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "lastkeyframelocation");
> > + flv->lastkeyframelocation_offset = avio_tell(pb);
> > + flv->lastkeyframelocation = 0;
> > + put_amf_double(pb, 0);
> > + metadata_count++;
> > +
> > + put_amf_string(pb, "keyframes");
> > + put_amf_byte(pb, AMF_DATA_TYPE_OBJECT);
> > + metadata_count++;
> > +
> > + flv->keyframes_info_offset = avio_tell(pb);
> > + }
> > +
> > put_amf_string(pb, "");
> > avio_w8(pb, AMF_END_OF_OBJECT);
> >
> > /* write total size of tag */
> > - data_size = avio_tell(pb) - metadata_size_pos - 10;
> > + flv->metadata_totalsize = avio_tell(pb) - flv->metadata_size_pos -
> 10;
> >
> > avio_seek(pb, metadata_count_pos, SEEK_SET);
> > avio_wb32(pb, metadata_count);
> >
> > - avio_seek(pb, metadata_size_pos, SEEK_SET);
> > - avio_wb24(pb, data_size);
> > - avio_skip(pb, data_size + 10 - 3);
> > - avio_wb32(pb, data_size + 11);
> > + avio_seek(pb, flv->metadata_size_pos, SEEK_SET);
> > + avio_wb24(pb, flv->metadata_totalsize);
> > + avio_skip(pb, flv->metadata_totalsize + 10 - 3);
> > + flv->metadata_totalsize_pos = avio_tell(pb);
> > + avio_wb32(pb, flv->metadata_totalsize + 11);
> > }
> >
> > static int unsupported_codec(AVFormatContext *s,
> > @@ -416,6 +531,111 @@ static void flv_write_codec_header(AVFormatContext*
> s, AVCodecParameters* par) {
> > }
> > }
> >
>
> > +static int flv_append_keyframe_info(AVFormatContext *s, FLVContext
> *flv, double ts, int64_t pos)
> > +{
> > + FLVFileposition *position = av_malloc(sizeof(FLVFileposition));
> > +
> > + if (!position) {
> > + av_log(s, AV_LOG_WARNING, "no mem for add keyframe index!\n");
> > + return AVERROR(ENOMEM);
> > + }
> > +
> > + position->keyframe_timestamp = ts;
> > + position->keyframe_position = pos;
> > +
> > + if (flv->filepositions_count) {
> > + flv->filepositions = position;
> > + flv->head_filepositions = flv->filepositions;
> > + position->next = NULL;
> > + } else {
> > + flv->filepositions->next = position;
> > + position->next = NULL;
> > + flv->filepositions = flv->filepositions->next;
> > + }
> > +
> > + flv->filepositions_count++;
> > +
> > + return 0;
> > +}
>
> an array should be more space efficient than a linked list
>
array have max limit, if this is used in recording living stream to flv,
maybe linked list is better than array.
> maybe i miss something but
> cant you simply use av_add_index_entry() ?
>
>
> > +
>
> > +static int shift_data(AVFormatContext *s)
> > +{
> > + int ret = 0;
> > + int n = 0;
> > + int metadata_size = 0;
> > + FLVContext *flv = s->priv_data;
> > + int64_t pos, pos_end = avio_tell(s->pb);
> > + uint8_t *buf, *read_buf[2];
> > + int read_buf_id = 0;
> > + int read_size[2];
> > + AVIOContext *read_pb;
> > +
>
> > + metadata_size = flv->filepositions_count * 9 * 2 + 10; /*
> filepositions and times value */
>
> The multiplications need checks for overflow i think or the type
> must be larger (int64) if filepositions_count is 32 or oterwise
> limited
>
>
> > + metadata_size += 2 + 13; /* filepositions String */
> > + metadata_size += 2 + 5; /* times String */
> > + metadata_size += 3; /* Object end */
> > +
> > + flv->keyframe_index_size = metadata_size;
> > +
> > + if (metadata_size < 0)
> > + return metadata_size;
> > +
>
> > + buf = av_malloc(metadata_size * 2);
>
> av_malloc_array()
>
> [...]
> --
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> While the State exists there can be no freedom; when there is freedom there
> will be no State. -- Vladimir Lenin
>
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