1
0
mirror of https://github.com/mpv-player/mpv synced 2024-12-24 07:42:17 +00:00
mpv/demux/packet.c
wm4 6d36fad83c video: make decoder wrapper a filter
Move dec_video.c to filters/f_decoder_wrapper.c. It essentially becomes
a source filter. vd.h mostly disappears, because mp_filter takes care of
the dataflow, but its remains are in struct mp_decoder_fns.

One goal is to simplify dataflow by letting the filter framework handle
it (or more accurately, using its conventions). One result is that the
decode calls disappear from video.c, because we simply connect the
decoder wrapper and the filter chain with mp_pin_connect().

Another goal is to eventually remove the code duplication between the
audio and video paths for this. This commit prepares for this by trying
to make f_decoder_wrapper.c extensible, so it can be used for audio as
well later.

Decoder framedropping changes a bit. It doesn't seem to be worse than
before, and it's an obscure feature, so I'm content with its new state.
Some special code that was apparently meant to avoid dropping too many
frames in a row is removed, though.

I'm not sure how the source code tree should be organized. For one,
video/decode/vd_lavc.c is the only file in its directory, which is a bit
annoying.
2018-01-30 03:10:27 -08:00

209 lines
6.2 KiB
C

/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <libavcodec/avcodec.h>
#include <libavutil/intreadwrite.h>
#include "config.h"
#include "common/av_common.h"
#include "common/common.h"
#include "packet.h"
static void packet_destroy(void *ptr)
{
struct demux_packet *dp = ptr;
av_packet_unref(dp->avpacket);
}
// This actually preserves only data and side data, not PTS/DTS/pos/etc.
// It also allows avpkt->data==NULL with avpkt->size!=0 - the libavcodec API
// does not allow it, but we do it to simplify new_demux_packet().
struct demux_packet *new_demux_packet_from_avpacket(struct AVPacket *avpkt)
{
if (avpkt->size > 1000000000)
return NULL;
struct demux_packet *dp = talloc(NULL, struct demux_packet);
talloc_set_destructor(dp, packet_destroy);
*dp = (struct demux_packet) {
.pts = MP_NOPTS_VALUE,
.dts = MP_NOPTS_VALUE,
.duration = -1,
.pos = -1,
.start = MP_NOPTS_VALUE,
.end = MP_NOPTS_VALUE,
.stream = -1,
.avpacket = talloc_zero(dp, AVPacket),
.kf_seek_pts = MP_NOPTS_VALUE,
};
av_init_packet(dp->avpacket);
int r = -1;
if (avpkt->data) {
// We hope that this function won't need/access AVPacket input padding,
// because otherwise new_demux_packet_from() wouldn't work.
r = av_packet_ref(dp->avpacket, avpkt);
} else {
r = av_new_packet(dp->avpacket, avpkt->size);
}
if (r < 0) {
*dp->avpacket = (AVPacket){0};
talloc_free(dp);
return NULL;
}
dp->buffer = dp->avpacket->data;
dp->len = dp->avpacket->size;
return dp;
}
// (buf must include proper padding)
struct demux_packet *new_demux_packet_from_buf(struct AVBufferRef *buf)
{
if (!buf)
return NULL;
AVPacket pkt = {
.size = buf->size,
.data = buf->data,
.buf = buf,
};
return new_demux_packet_from_avpacket(&pkt);
}
// Input data doesn't need to be padded.
struct demux_packet *new_demux_packet_from(void *data, size_t len)
{
if (len > INT_MAX)
return NULL;
AVPacket pkt = { .data = data, .size = len };
return new_demux_packet_from_avpacket(&pkt);
}
struct demux_packet *new_demux_packet(size_t len)
{
if (len > INT_MAX)
return NULL;
AVPacket pkt = { .data = NULL, .size = len };
return new_demux_packet_from_avpacket(&pkt);
}
void demux_packet_shorten(struct demux_packet *dp, size_t len)
{
assert(len <= dp->len);
dp->len = len;
memset(dp->buffer + dp->len, 0, AV_INPUT_BUFFER_PADDING_SIZE);
}
void free_demux_packet(struct demux_packet *dp)
{
talloc_free(dp);
}
void demux_packet_copy_attribs(struct demux_packet *dst, struct demux_packet *src)
{
dst->pts = src->pts;
dst->dts = src->dts;
dst->duration = src->duration;
dst->pos = src->pos;
dst->segmented = src->segmented;
dst->start = src->start;
dst->end = src->end;
dst->codec = src->codec;
dst->keyframe = src->keyframe;
dst->stream = src->stream;
}
struct demux_packet *demux_copy_packet(struct demux_packet *dp)
{
struct demux_packet *new = NULL;
if (dp->avpacket) {
new = new_demux_packet_from_avpacket(dp->avpacket);
} else {
// Some packets might be not created by new_demux_packet*().
new = new_demux_packet_from(dp->buffer, dp->len);
}
if (!new)
return NULL;
demux_packet_copy_attribs(new, dp);
return new;
}
#define ROUND_ALLOC(s) MP_ALIGN_UP(s, 64)
// Attempt to estimate the total memory consumption of the given packet.
// This is important if we store thousands of packets and not to exceed
// user-provided limits. Of course we can't know how much memory internal
// fragmentation of the libc memory allocator will waste.
// Note that this should return a "stable" value - e.g. if a new packet ref
// is created, this should return the same value with the new ref. (This
// implies the value is not exact and does not return the actual size of
// memory wasted due to internal fragmentation.)
size_t demux_packet_estimate_total_size(struct demux_packet *dp)
{
size_t size = ROUND_ALLOC(sizeof(struct demux_packet));
size += ROUND_ALLOC(dp->len);
if (dp->avpacket) {
size += ROUND_ALLOC(sizeof(AVPacket));
size += ROUND_ALLOC(sizeof(AVBufferRef));
size += 64; // upper bound estimate on sizeof(AVBuffer)
size += ROUND_ALLOC(dp->avpacket->side_data_elems *
sizeof(dp->avpacket->side_data[0]));
for (int n = 0; n < dp->avpacket->side_data_elems; n++)
size += ROUND_ALLOC(dp->avpacket->side_data[n].size);
}
return size;
}
int demux_packet_set_padding(struct demux_packet *dp, int start, int end)
{
#if LIBAVCODEC_VERSION_MICRO >= 100
if (!start && !end)
return 0;
if (!dp->avpacket)
return -1;
uint8_t *p = av_packet_new_side_data(dp->avpacket, AV_PKT_DATA_SKIP_SAMPLES, 10);
if (!p)
return -1;
AV_WL32(p + 0, start);
AV_WL32(p + 4, end);
#endif
return 0;
}
int demux_packet_add_blockadditional(struct demux_packet *dp, uint64_t id,
void *data, size_t size)
{
#if LIBAVCODEC_VERSION_MICRO >= 100
if (!dp->avpacket)
return -1;
uint8_t *sd = av_packet_new_side_data(dp->avpacket,
AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
8 + size);
if (!sd)
return -1;
AV_WB64(sd, id);
if (size > 0)
memcpy(sd + 8, data, size);
#endif
return 0;
}