[FFmpeg-devel] [PATCH] avformat/flvenc: add add_keyframe_index option
Steven Liu
lq at chinaffmpeg.org
Sat Nov 5 14:42:49 EET 2016
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>
Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
---
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..c18a6eb 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;
+}
+
+static int shift_data(AVFormatContext *s)
+{
+ int ret = 0;
+ int n = 0;
+ int64_t 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 */
+ 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_array(metadata_size, 2);
+ if (!buf) {
+ return AVERROR(ENOMEM);
+ }
+ read_buf[0] = buf;
+ read_buf[1] = buf + metadata_size;
+
+ avio_seek(s->pb, flv->metadata_size_pos, SEEK_SET);
+ avio_wb24(s->pb, flv->metadata_totalsize + metadata_size);
+
+ avio_seek(s->pb, flv->metadata_totalsize_pos, SEEK_SET);
+ avio_wb32(s->pb, flv->metadata_totalsize + 11 + metadata_size);
+ avio_seek(s->pb, pos_end, SEEK_SET);
+
+ /* Shift the data: the AVIO context of the output can only be used for
+ * writing, so we re-open the same output, but for reading. It also avoids
+ * a read/seek/write/seek back and forth. */
+ avio_flush(s->pb);
+ ret = s->io_open(s, &read_pb, s->filename, AVIO_FLAG_READ, NULL);
+ if (ret < 0) {
+ av_log(s, AV_LOG_ERROR, "Unable to re-open %s output file for "
+ "the second pass (add_keyframe_index)\n", s->filename);
+ goto end;
+ }
+
+ /* 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 *filepositions* and *times* size */
+ read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id], metadata_size); \
+ read_buf_id ^= 1;
+ do {
+
+ read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id], metadata_size); \
+ read_buf_id ^= 1;
+ n = read_size[read_buf_id];
+ if (n < 0)
+ break;
+ avio_write(s->pb, read_buf[read_buf_id], n);
+ pos += n;
+ } while (pos <= pos_end);
+
+ ff_format_io_close(s, &read_pb);
+
+end:
+ av_free(buf);
+ return ret;
+}
+
+
static int flv_write_header(AVFormatContext *s)
{
int i;
@@ -521,17 +741,75 @@ static int flv_write_header(AVFormatContext *s)
flv_write_codec_header(s, s->streams[i]->codecpar);
}
+ flv->datastart_offset = avio_tell(pb);
return 0;
}
static int flv_write_trailer(AVFormatContext *s)
{
int64_t file_size;
-
AVIOContext *pb = s->pb;
FLVContext *flv = s->priv_data;
- int i;
+ int build_keyframes_idx = flv->flags & FLV_ADD_KEYFRAME_INDEX;
+ int i, res;
+ int64_t cur_pos = avio_tell(s->pb);
+
+ if (build_keyframes_idx) {
+ FLVFileposition *newflv_posinfo, *p;
+
+ avio_seek(pb, flv->videosize_offset, SEEK_SET);
+ put_amf_double(pb, flv->videosize);
+
+ avio_seek(pb, flv->audiosize_offset, SEEK_SET);
+ put_amf_double(pb, flv->audiosize);
+
+ avio_seek(pb, flv->lasttimestamp_offset, SEEK_SET);
+ put_amf_double(pb, flv->lasttimestamp);
+
+ avio_seek(pb, flv->lastkeyframetimestamp_offset, SEEK_SET);
+ put_amf_double(pb, flv->lastkeyframetimestamp);
+ avio_seek(pb, flv->lastkeyframelocation_offset, SEEK_SET);
+ put_amf_double(pb, flv->lastkeyframelocation + flv->keyframe_index_size);
+ avio_seek(pb, cur_pos, SEEK_SET);
+
+ res = shift_data(s);
+ if (res < 0) {
+ goto end;
+ }
+ avio_seek(pb, flv->keyframes_info_offset, SEEK_SET);
+ put_amf_string(pb, "filepositions");
+ put_amf_dword_array(pb, flv->filepositions_count);
+ for (newflv_posinfo = flv->head_filepositions; newflv_posinfo; newflv_posinfo = newflv_posinfo->next) {
+ put_amf_double(pb, newflv_posinfo->keyframe_position + flv->keyframe_index_size);
+ }
+
+ put_amf_string(pb, "times");
+ put_amf_dword_array(pb, flv->filepositions_count);
+ for (newflv_posinfo = flv->head_filepositions; newflv_posinfo; newflv_posinfo = newflv_posinfo->next) {
+ put_amf_double(pb, newflv_posinfo->keyframe_timestamp);
+ }
+
+ newflv_posinfo = flv->head_filepositions;
+ while (newflv_posinfo) {
+ p = newflv_posinfo->next;
+ if (p) {
+ newflv_posinfo->next = p->next;
+ av_free(p);
+ p = NULL;
+ } else {
+ av_free(newflv_posinfo);
+ newflv_posinfo = NULL;
+ }
+ }
+
+ put_amf_string(pb, "");
+ avio_w8(pb, AMF_END_OF_OBJECT);
+
+ avio_seek(pb, cur_pos + flv->keyframe_index_size, SEEK_SET);
+ }
+
+end:
if (flv->flags & FLV_NO_SEQUENCE_END) {
av_log(s, AV_LOG_DEBUG, "FLV no sequence end mode open\n");
} else {
@@ -547,6 +825,11 @@ static int flv_write_trailer(AVFormatContext *s)
file_size = avio_tell(pb);
+ if (build_keyframes_idx) {
+ flv->datasize = file_size - flv->datastart_offset;
+ avio_seek(pb, flv->datasize_offset, SEEK_SET);
+ put_amf_double(pb, flv->datasize);
+ }
if (pb->seekable) {
/* update information */
if (avio_seek(pb, flv->duration_offset, SEEK_SET) < 0) {
@@ -574,6 +857,7 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
int size = pkt->size;
uint8_t *data = NULL;
int flags = -1, flags_size, ret;
+ int64_t cur_offset = avio_tell(pb);
if (par->codec_id == AV_CODEC_ID_VP6F || par->codec_id == AV_CODEC_ID_VP6A ||
par->codec_id == AV_CODEC_ID_VP6 || par->codec_id == AV_CODEC_ID_AAC)
@@ -727,6 +1011,32 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
pkt->pts + flv->delay + pkt->duration);
}
+ if (flv->flags & FLV_ADD_KEYFRAME_INDEX) {
+ switch (par->codec_type) {
+ case AVMEDIA_TYPE_VIDEO:
+ flv->videosize += (avio_tell(pb) - cur_offset);
+ flv->lasttimestamp = flv->acurframeindex / flv->framerate;
+ if (pkt->flags & AV_PKT_FLAG_KEY) {
+ double ts = flv->acurframeindex / flv->framerate;
+ int64_t pos = cur_offset;
+
+ flv->lastkeyframetimestamp = flv->acurframeindex / flv->framerate;
+ flv->lastkeyframelocation = pos;
+ flv_append_keyframe_info(s, flv, ts, pos);
+ }
+ flv->acurframeindex++;
+ break;
+
+ case AVMEDIA_TYPE_AUDIO:
+ flv->audiosize += (avio_tell(pb) - cur_offset);
+ break;
+
+ default:
+ av_log(s, AV_LOG_WARNING, "par->codec_type is type = [%d]\n", par->codec_type);
+ break;
+ }
+ }
+
av_free(data);
return pb->error;
@@ -736,6 +1046,7 @@ static const AVOption options[] = {
{ "flvflags", "FLV muxer flags", offsetof(FLVContext, flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
{ "aac_seq_header_detect", "Put AAC sequence header based on stream data", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_AAC_SEQ_HEADER_DETECT}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
{ "no_sequence_end", "disable sequence end for FLV", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_NO_SEQUENCE_END}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
+ { "add_keyframe_index", "Add keyframe index metadata", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_ADD_KEYFRAME_INDEX}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
{ NULL },
};
--
1.7.1
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