Re: [FFmpeg-devel] [PATCH] avformat/flvenc: add build_keyframes_index option

[Lou Logan]

On Thu, Nov 3, 2016, at 05:05 AM, Steven Liu wrote:
> Build keyframes index information into metadata.

Can be simplified to:

"Add keyframe index metadata."

> Be used to http VOD flv.

The above phrase is not very descriptive. I suggest something like:

"Used to facilitate seeking; particularly for HTTP pseudo streaming."

> Signed-off-by: Steven Liu 
> ---
>  doc/muxers.texi  |3 +
>  libavformat/flvenc.c |  323
>  --
>  2 files changed, 317 insertions(+), 9 deletions(-)
> 
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index 488ed43..1df7d97 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.
> +
> +@item build_keyframes_index

"add_keyframe_index" makes more sense to me.

> +Build keyframes index infomations into flv metadata. Be used to http
> VOD..

You can reuse the commit message sentences here.

>  @end table
>  @end table
>  
> diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
> index e50f8e4..1f1b608 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_BUILD_KEYFRAME_IDX = (1 << 2),

I would name it FLV_ADD_KEYFRAME_INDEX or similar, but I'll leave it to
whatever you prefer.

[...]
> +if (ret < 0) {
> +av_log(s, AV_LOG_ERROR, "Unable to re-open %s output file for "
> +   "the second pass (faststart)\n", s->filename);
> +goto end;
> +}

"faststart" implies that an option or value named "faststart" was used.
Should be renamed.

> +/* mark the end of the shift to up to the last data we wrote, and
> get ready
> + * for writing */
> +pos_end = avio_tell(s->pb);
> +avio_seek(s->pb, flv->keyframes_info_offset + metadata_size,
> SEEK_SET);
> +
> +/* start reading at where the keyframe index information will be
> placed */
> +avio_seek(read_pb, flv->keyframes_info_offset, SEEK_SET);
> +pos = avio_tell(read_pb);
> +
> +/* shift data by chunk of at most keyframe infomations size */

I don't understand the above sentence.

[...]
> +{ "build_keyframes_index", "Build keyframes index information into
> metadata", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_BUILD_KEYFRAME_IDX},
> INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
>  { NULL },
>  };

I would change it to:

"add_keyframe_index", "Add keyframe index metadata"
___
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

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

[Steven Liu]

Build keyframes index information into metadata.
Be used to http VOD flv.

Signed-off-by: Steven Liu 
---
 doc/muxers.texi  |3 +
 libavformat/flvenc.c |  323 --
 2 files changed, 317 insertions(+), 9 deletions(-)

diff --git a/doc/muxers.texi b/doc/muxers.texi
index 488ed43..1df7d97 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.
+
+@item build_keyframes_index
+Build keyframes index infomations into flv metadata. Be used to http VOD..
 @end table
 @end table
 
diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index e50f8e4..1f1b608 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_BUILD_KEYFRAME_IDX = (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_BUILD_KEYFRAME_IDX) {
+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++;
+
+