[FFmpeg-devel] [PATCH v1] avformat/flvenc: add add_keyframe_index option

Steven Liu lingjiujianke at gmail.com
Fri Nov 4 14:59:25 EET 2016


2016-11-04 20:58 GMT+08:00 Steven Liu <lingjiujianke at gmail.com>:

>
>
> 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
>>
> ok

>
>>
>> > +    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()
>>
> ok

>
>> [...]
>> --
>> 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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>>
>>
>


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