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nut: Support experimental NUT 4 features

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Add the low overhead pipe mode and the extended broadcast mode.
Export the options as 'syncponts' since it impacts only that.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This commit is contained in:
Luca Barbato 2014-03-06 17:58:34 +01:00
parent 6d212599aa
commit c94e2e85cb
5 changed files with 112 additions and 9 deletions
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17
doc/muxers.texi
View File

@ -444,6 +444,23 @@ Alternatively you can write the command as:
avconv -benchmark -i INPUT -f null -
@end example
@section nut
@table @option
@item -syncpoints @var{flags}
Change the syncpoint usage in nut:
@table @option
@item @var{default} use the normal low-overhead seeking aids.
@item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
@item @var{timestamped} extend the syncpoint with a wallclock field.
@end table
The @var{none} and @var{timestamped} flags are experimental.
@end table
@example
avconv -i INPUT -f_strict experimental -syncpoints none - | processor
@end example
@section ogg
Ogg container muxer.

21
doc/nut.texi
View File

@ -17,6 +17,27 @@ subtitle and user-defined streams in a simple, yet efficient, way.
It was created by a group of FFmpeg and MPlayer developers in 2003
and was finalized in 2008.
@chapter Modes
NUT has some variants signaled by using the flags field in its main header.
@multitable @columnfractions .4 .4
@item BROADCAST @tab Extend the syncpoint to report the sender wallclock
@item PIPE @tab Omit completely the syncpoint
@end multitable
@section BROADCAST
The BROADCAST variant provides a secondary time reference to facilitate
detecting endpoint latency and network delays.
It assumes all the endpoint clocks are syncronized.
To be used in real-time scenarios.
@section PIPE
The PIPE variant assumes NUT is used as non-seekable intermediate container,
by not using syncpoint removes unneeded overhead and reduces the overall
memory usage.
@chapter Container-specific codec tags
@section Generic raw YUVA formats

9
libavformat/nut.h
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@ -36,7 +36,9 @@
#define MAX_DISTANCE (1024*32-1)
#define NUT_VERSION 3
#define NUT_MAX_VERSION 4
#define NUT_STABLE_VERSION 3
#define NUT_MIN_VERSION 2
typedef enum{
FLAG_KEY = 1, ///<if set, frame is keyframe
@ -85,6 +87,7 @@ typedef struct ChapterContext {
} ChapterContext;
typedef struct NUTContext {
const AVClass *av_class;
AVFormatContext *avf;
// int written_packet_size;
// int64_t packet_start;
@ -100,6 +103,10 @@ typedef struct NUTContext {
int header_count;
AVRational *time_base;
struct AVTreeNode *syncpoints;
#define NUT_BROADCAST 1 // use extended syncpoints
#define NUT_PIPE 2 // do not write syncpoints
int flags;
int version; // version currently in use
} NUTContext;
extern const AVCodecTag ff_nut_subtitle_tags[];

29
libavformat/nutdec.c
View File

@ -213,8 +213,8 @@ static int decode_main_header(NUTContext *nut)
end = get_packetheader(nut, bc, 1, MAIN_STARTCODE);
end += avio_tell(bc);
tmp = ffio_read_varlen(bc);
if (tmp < 2 && tmp > NUT_VERSION) {
nut->version = ffio_read_varlen(bc);
if (tmp < NUT_MIN_VERSION && tmp > NUT_MAX_VERSION) {
av_log(s, AV_LOG_ERROR, "Version %"PRId64" not supported.\n",
tmp);
return AVERROR(ENOSYS);
@ -320,6 +320,11 @@ static int decode_main_header(NUTContext *nut)
assert(nut->header_len[0] == 0);
}
// flags had been effectively introduced in version 4
if (nut->version > NUT_STABLE_VERSION) {
nut->flags = ffio_read_varlen(bc);
}
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
return AVERROR_INVALIDDATA;
@ -547,6 +552,14 @@ static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr)
ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count],
tmp / nut->time_base_count);
if (nut->flags & NUT_BROADCAST) {
tmp = ffio_read_varlen(bc);
av_log(s, AV_LOG_VERBOSE, "Syncpoint wallclock %"PRId64"\n",
av_rescale_q(tmp / nut->time_base_count,
nut->time_base[tmp % nut->time_base_count],
AV_TIME_BASE_Q));
}
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
return AVERROR_INVALIDDATA;
@ -728,7 +741,8 @@ static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id,
int size, flags, size_mul, pts_delta, i, reserved_count;
uint64_t tmp;
if (avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance) {
if (!(nut->flags & NUT_PIPE) &&
avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance) {
av_log(s, AV_LOG_ERROR,
"Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n",
avio_tell(bc), nut->last_syncpoint_pos, nut->max_distance);
@ -781,8 +795,9 @@ static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id,
if (flags & FLAG_CHECKSUM) {
avio_rb32(bc); // FIXME check this
} else if (size > 2 * nut->max_distance || FFABS(stc->last_pts - *pts) >
stc->max_pts_distance) {
} else if (!(nut->flags & NUT_PIPE) &&
size > 2 * nut->max_distance ||
FFABS(stc->last_pts - *pts) > stc->max_pts_distance) {
av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
return AVERROR_INVALIDDATA;
}
@ -933,6 +948,10 @@ static int read_seek(AVFormatContext *s, int stream_index,
int64_t pos, pos2, ts;
int i;
if (nut->flags & NUT_PIPE) {
return AVERROR(ENOSYS);
}
if (st->index_entries) {
int index = av_index_search_timestamp(st, pts, flags);
if (index < 0)

45
libavformat/nutenc.c
View File

@ -25,6 +25,8 @@
#include "libavutil/mathematics.h"
#include "libavutil/tree.h"
#include "libavutil/dict.h"
#include "libavutil/time.h"
#include "libavutil/opt.h"
#include "libavcodec/mpegaudiodata.h"
#include "nut.h"
#include "internal.h"
@ -325,7 +327,7 @@ static void write_mainheader(NUTContext *nut, AVIOContext *bc)
tmp_head_idx;
int64_t tmp_match;
ff_put_v(bc, NUT_VERSION);
ff_put_v(bc, nut->version);
ff_put_v(bc, nut->avf->nb_streams);
ff_put_v(bc, nut->max_distance);
ff_put_v(bc, nut->time_base_count);
@ -405,6 +407,9 @@ static void write_mainheader(NUTContext *nut, AVIOContext *bc)
ff_put_v(bc, nut->header_len[i]);
avio_write(bc, nut->header[i], nut->header_len[i]);
}
// flags had been effectively introduced in version 4
if (nut->version > NUT_STABLE_VERSION)
ff_put_v(bc, nut->flags);
}
static int write_streamheader(AVFormatContext *avctx, AVIOContext *bc,
@ -643,6 +648,16 @@ static int nut_write_header(AVFormatContext *s)
nut->avf = s;
nut->version = NUT_STABLE_VERSION + !!nut->flags;
if (nut->flags && s->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
av_log(s, AV_LOG_ERROR,
"The additional syncpoint modes require version %d, "
"that is currently not finalized, "
"please set -f_strict experimental in order to enable it.\n",
nut->version);
return AVERROR_EXPERIMENTAL;
}
nut->stream = av_mallocz(sizeof(StreamContext) * s->nb_streams);
if (s->nb_chapters)
nut->chapter = av_mallocz(sizeof(ChapterContext) * s->nb_chapters);
@ -789,7 +804,8 @@ static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
//FIXME: Ensure store_sp is 1 in the first place.
if (store_sp) {
if (store_sp &&
(!(nut->flags & NUT_PIPE) || nut->last_syncpoint_pos == INT_MIN)) {
Syncpoint *sp, dummy = { .pos = INT64_MAX };
ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
@ -815,6 +831,11 @@ static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
return ret;
put_tt(nut, nus->time_base, dyn_bc, pkt->dts);
ff_put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos) >> 4 : 0);
if (nut->flags & NUT_BROADCAST) {
put_tt(nut, nus->time_base, dyn_bc,
av_rescale_q(av_gettime(), AV_TIME_BASE_Q, *nus->time_base));
}
put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
if ((ret = ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0 /*unused*/, pkt->dts)) < 0)
@ -917,7 +938,7 @@ static int nut_write_packet(AVFormatContext *s, AVPacket *pkt)
nus->last_pts = pkt->pts;
//FIXME just store one per syncpoint
if (flags & FLAG_KEY)
if (flags & FLAG_KEY && !(nut->flags & NUT_PIPE))
av_add_index_entry(
s->streams[pkt->stream_index],
nut->last_syncpoint_pos,
@ -945,6 +966,23 @@ static int nut_write_trailer(AVFormatContext *s)
return 0;
}
#define OFFSET(x) offsetof(NUTContext, x)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "syncpoints", "NUT syncpoint behaviour", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, INT_MIN, INT_MAX, E, "syncpoints" },
{ "default", "", 0, AV_OPT_TYPE_CONST, {.i64 = 0}, INT_MIN, INT_MAX, E, "syncpoints" },
{ "none", "Disable syncpoints, low overhead and unseekable", 0, AV_OPT_TYPE_CONST, {.i64 = NUT_PIPE}, INT_MIN, INT_MAX, E, "syncpoints" },
{ "timestamped", "Extend syncpoints with a wallclock timestamp", 0, AV_OPT_TYPE_CONST, {.i64 = NUT_BROADCAST}, INT_MIN, INT_MAX, E, "syncpoints" },
{ NULL },
};
static const AVClass class = {
.class_name = "nutenc",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_nut_muxer = {
.name = "nut",
.long_name = NULL_IF_CONFIG_SMALL("NUT"),
@ -959,4 +997,5 @@ AVOutputFormat ff_nut_muxer = {
.write_trailer = nut_write_trailer,
.flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
.codec_tag = ff_nut_codec_tags,
.priv_class = &class,
};