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mirror of https://github.com/mpv-player/mpv synced 2024-11-11 00:15:33 +01:00

demux: avoid a copy of demux packets with lavf, reduce padding

When demux_lavf read a new packet it used to copy the data from
libavformat's struct AVPacket to struct demux_packet and then free the
lavf packet. Change it to instead keep the AVPacket allocated and
point demux_packet fields to the buffer in that.

Also change MP_INPUT_BUFFER_PADDING_SIZE to 8 which matches
FF_INPUT_BUFFER_PADDING SIZE; demux_lavf packets won't have more
padding now anyway (it was increased from 8 earlier when
FF_INPUT_BUFFER_PADDING_SIZE was increased in libavcodec, but that
change was reverted).
This commit is contained in:
Uoti Urpala 2011-08-19 04:59:01 +03:00
parent 6ec60c976f
commit 6e8d420a41
3 changed files with 45 additions and 26 deletions

View File

@ -743,10 +743,15 @@ static void check_internet_radio_hack(struct demuxer *demuxer)
}
}
static int destroy_avpacket(void *pkt)
{
av_free_packet(pkt);
return 0;
}
static int demux_lavf_fill_buffer(demuxer_t *demux, demux_stream_t *dsds)
{
lavf_priv_t *priv = demux->priv;
AVPacket pkt;
demux_packet_t *dp;
demux_stream_t *ds;
int id;
@ -754,8 +759,12 @@ static int demux_lavf_fill_buffer(demuxer_t *demux, demux_stream_t *dsds)
demux->filepos = stream_tell(demux->stream);
if (av_read_frame(priv->avfc, &pkt) < 0)
AVPacket *pkt = talloc(NULL, AVPacket);
if (av_read_frame(priv->avfc, pkt) < 0) {
talloc_free(pkt);
return 0;
}
talloc_set_destructor(pkt, destroy_avpacket);
// handle any new streams that might have been added
for (id = priv->nb_streams_last; id < priv->avfc->nb_streams; id++)
@ -764,7 +773,7 @@ static int demux_lavf_fill_buffer(demuxer_t *demux, demux_stream_t *dsds)
priv->nb_streams_last = priv->avfc->nb_streams;
id = pkt.stream_index;
id = pkt->stream_index;
if (id == demux->audio->id || priv->internet_radio_hack) {
// audio
@ -787,39 +796,27 @@ static int demux_lavf_fill_buffer(demuxer_t *demux, demux_stream_t *dsds)
ds = demux->sub;
sub_utf8 = 1;
} else {
av_free_packet(&pkt);
talloc_free(pkt);
return 1;
}
if (0 /*pkt.destruct == av_destruct_packet*/) {
//ok kids, dont try this at home :)
dp = malloc(sizeof(demux_packet_t));
dp->len = pkt.size;
dp->next = NULL;
dp->refcount = 1;
dp->master = NULL;
dp->buffer = pkt.data;
pkt.destruct = NULL;
} else {
dp = new_demux_packet(pkt.size);
memcpy(dp->buffer, pkt.data, pkt.size);
av_free_packet(&pkt);
}
dp = new_demux_packet_fromdata(pkt->data, pkt->size);
dp->avpacket = pkt;
int64_t ts = priv->use_dts ? pkt.dts : pkt.pts;
int64_t ts = priv->use_dts ? pkt->dts : pkt->pts;
if (ts != AV_NOPTS_VALUE) {
dp->pts = ts * av_q2d(priv->avfc->streams[id]->time_base);
priv->last_pts = dp->pts * AV_TIME_BASE;
// always set duration for subtitles, even if AV_PKT_FLAG_KEY isn't set,
// otherwise they will stay on screen to long if e.g. ASS is demuxed
// from mkv
if ((ds == demux->sub || (pkt.flags & AV_PKT_FLAG_KEY)) &&
pkt.convergence_duration > 0)
dp->duration = pkt.convergence_duration *
if ((ds == demux->sub || (pkt->flags & AV_PKT_FLAG_KEY)) &&
pkt->convergence_duration > 0)
dp->duration = pkt->convergence_duration *
av_q2d(priv->avfc->streams[id]->time_base);
}
dp->pos = demux->filepos;
dp->flags = !!(pkt.flags & AV_PKT_FLAG_KEY);
dp->flags = !!(pkt->flags & AV_PKT_FLAG_KEY);
// append packet to DS stream:
ds_add_packet(ds, dp);
return 1;

View File

@ -176,7 +176,7 @@ const demuxer_desc_t *const demuxer_list[] = {
NULL
};
struct demux_packet *new_demux_packet(size_t len)
static struct demux_packet *create_packet(size_t len)
{
if (len > 1000000000) {
mp_msg(MSGT_DEMUXER, MSGL_FATAL, "Attempt to allocate demux packet "
@ -194,6 +194,13 @@ struct demux_packet *new_demux_packet(size_t len)
dp->refcount = 1;
dp->master = NULL;
dp->buffer = NULL;
dp->avpacket = NULL;
return dp;
}
struct demux_packet *new_demux_packet(size_t len)
{
struct demux_packet *dp = create_packet(len);
dp->buffer = malloc(len + MP_INPUT_BUFFER_PADDING_SIZE);
if (!dp->buffer) {
mp_msg(MSGT_DEMUXER, MSGL_FATAL, "Memory allocation failure!\n");
@ -203,6 +210,14 @@ struct demux_packet *new_demux_packet(size_t len)
return dp;
}
// data must already have suitable padding
struct demux_packet *new_demux_packet_fromdata(void *data, size_t len)
{
struct demux_packet *dp = create_packet(len);
dp->buffer = data;
return dp;
}
void resize_demux_packet(struct demux_packet *dp, size_t len)
{
if (len > 1000000000) {
@ -237,7 +252,10 @@ void free_demux_packet(struct demux_packet *dp)
if (dp->master == NULL) { //dp is a master packet
dp->refcount--;
if (dp->refcount == 0) {
free(dp->buffer);
if (dp->avpacket)
talloc_free(dp->avpacket);
else
free(dp->buffer);
free(dp);
}
return;

View File

@ -122,7 +122,8 @@ enum timestamp_type {
#define SEEK_FORWARD (1 << 2)
#define SEEK_BACKWARD (1 << 3)
#define MP_INPUT_BUFFER_PADDING_SIZE 64
// demux_lavf can pass lavf buffers using FF_INPUT_BUFFER_PADDING_SIZE instead
#define MP_INPUT_BUFFER_PADDING_SIZE 8
// Holds one packet/frame/whatever
typedef struct demux_packet {
@ -136,6 +137,7 @@ typedef struct demux_packet {
int refcount; // counter for the master packet, if 0, buffer can be free()d
struct demux_packet *master; //in clones, pointer to the master packet
struct demux_packet *next;
struct AVPacket *avpacket; // original libavformat packet (demux_lavf)
} demux_packet_t;
typedef struct demux_stream {
@ -302,6 +304,8 @@ typedef struct {
} demux_program_t;
struct demux_packet *new_demux_packet(size_t len);
// data must already have suitable padding
struct demux_packet *new_demux_packet_fromdata(void *data, size_t len);
void resize_demux_packet(struct demux_packet *dp, size_t len);
struct demux_packet *clone_demux_packet(struct demux_packet *pack);
void free_demux_packet(struct demux_packet *dp);