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ao_lavc: remove audio offset hack to ease supporting planar audio. 

Now to shift audio pts when outputting to e.g. avi, you need an explicit
facility to insert/remove initial samples, to avoid initial regions of
the video to be sped up/slowed down.

One such facility is the delay filter in libavfilter.
This commit is contained in:
Rudolf Polzer 2013-11-11 13:03:22 +01:00
parent 8ff577a2f3
commit 149ab3afa2
1 changed files with 11 additions and 66 deletions
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77
audio/out/ao_lavc.c
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@ -50,8 +50,6 @@ struct priv {
int pcmhack;
int aframesize;
int aframecount;
int offset;
int offset_left;
int64_t savepts;
int framecount;
int64_t lastpts;
@ -270,9 +268,6 @@ out_takefirst:
ac->savepts = MP_NOPTS_VALUE;
ac->lastpts = MP_NOPTS_VALUE;
ac->offset = ac->stream->codec->sample_rate *
encode_lavc_getoffset(ao->encode_lavc_ctx, ac->stream);
ac->offset_left = ac->offset;
ao->untimed = true;
ao->priv = ac;
@ -451,7 +446,6 @@ static int play(struct ao *ao, void *data, int len, int flags)
struct priv *ac = ao->priv;
struct encode_lavc_context *ectx = ao->encode_lavc_ctx;
int bufpos = 0;
int64_t ptsoffset;
void *paddingbuf = NULL;
double nextpts;
double pts = ao->pts;
@ -540,63 +534,10 @@ static int play(struct ao *ao, void *data, int len, int flags)
// Absurd, as this range MUST contain at least one multiple of B.
}
ptsoffset = ac->offset;
// this basically just edits ao->apts for syncing purposes
if (ectx->options->copyts || ectx->options->rawts) {
// we do not send time sync data to the video side,
// but we always need the exact pts, even if zero
} else {
// here we must "simulate" the pts editing
// 1. if we have to skip stuff, we skip it
// 2. if we have to add samples, we add them
// 3. we must still adjust ptsoffset appropriately for AV sync!
// invariant:
// if no partial skipping is done, the first frame gets ao->apts passed as pts!
if (ac->offset_left < 0) {
if (ac->offset_left <= -len) {
// skip whole frame
ac->offset_left += len;
return len * ac->sample_size * ao->channels.num;
} else {
// skip part of this frame, buffer/encode the rest
bufpos -= ac->offset_left;
ptsoffset += ac->offset_left;
ac->offset_left = 0;
}
} else if (ac->offset_left > 0) {
// make a temporary buffer, filled with zeroes at the start
// (don't worry, only happens once)
paddingbuf = talloc_size(ac, ac->sample_size * ao->channels.num *
(ac->offset_left + len));
fill_with_padding(paddingbuf, ac->offset_left, ac->sample_size,
ac->sample_padding);
data = (char *) paddingbuf + ac->sample_size * ao->channels.num *
ac->offset_left;
bufpos -= ac->offset_left; // yes, negative!
ptsoffset += ac->offset_left;
ac->offset_left = 0;
// now adjust the bufpos so the final value of bufpos is positive!
/*
int cnt = (len - bufpos) / ac->aframesize;
int finalbufpos = bufpos + cnt * ac->aframesize;
*/
int finalbufpos = len - (len - bufpos) % ac->aframesize;
if (finalbufpos < 0) {
MP_WARN(ao, "cannot attain the "
"exact requested audio sync; shifting by %d frames\n",
-finalbufpos);
bufpos -= finalbufpos;
}
}
}
// Fix and apply the discontinuity pts offset.
if (!ectx->options->rawts && ectx->options->copyts) {
// fix the discontinuity pts offset
nextpts = pts + ptsoffset / (double) ao->samplerate;
nextpts = pts;
if (ectx->discontinuity_pts_offset == MP_NOPTS_VALUE) {
ectx->discontinuity_pts_offset = ectx->next_in_pts - nextpts;
}
@ -609,23 +550,27 @@ static int play(struct ao *ao, void *data, int len, int flags)
outpts = pts + ectx->discontinuity_pts_offset;
}
else
else {
outpts = pts;
}
// Shift pts by the pts offset first.
outpts += encode_lavc_getoffset(ectx, ac->stream);
while (len - bufpos >= ac->aframesize) {
encode(ao,
outpts + (bufpos + ptsoffset) / (double) ao->samplerate + encode_lavc_getoffset(ectx, ac->stream),
outpts + bufpos / (double) ao->samplerate,
(char *) data + ac->sample_size * bufpos * ao->channels.num);
bufpos += ac->aframesize;
}
talloc_free(paddingbuf);
// calculate expected pts of next audio frame
ac->expected_next_pts = pts + (bufpos + ptsoffset) / (double) ao->samplerate;
// Calculate expected pts of next audio frame (input side).
ac->expected_next_pts = pts + bufpos / (double) ao->samplerate;
// Set next allowed input pts value (input side).
if (!ectx->options->rawts && ectx->options->copyts) {
// set next allowed output pts value
nextpts = ac->expected_next_pts + ectx->discontinuity_pts_offset;
if (nextpts > ectx->next_in_pts)
ectx->next_in_pts = nextpts;