mirror of
https://github.com/mpv-player/mpv
synced 2024-12-26 17:12:36 +00:00
261506e36e
This commit makes audio decoding non-blocking. If e.g. the network is
too slow the playloop will just go to sleep, instead of blocking until
enough data is available.
For video, this was already done with commit 7083f88c
. For audio, it's
unfortunately much more complicated, because the audio decoder was used
in a blocking manner. Large changes are required to get around this.
The whole playback restart mechanism must be turned into a statemachine,
especially since it has close interactions with video restart. Lots of
video code is thus also changed.
(For the record, I don't think switching this code to threads would
make this conceptually easier: the code would still have to deal with
external input while blocked, so these in-between states do get visible
[and thus need to be handled] anyway. On the other hand, it certainly
should be possible to modularize this code a bit better.)
This will probably cause a bunch of regressions.
304 lines
9.4 KiB
C
304 lines
9.4 KiB
C
/*
|
|
* MPEG 1.0/2.0/2.5 audio layer I, II, III decoding with libmpg123
|
|
*
|
|
* Copyright (C) 2010-2013 Thomas Orgis <thomas@orgis.org>
|
|
*
|
|
* MPlayer is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* MPlayer 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
#include "config.h"
|
|
|
|
#include "ad.h"
|
|
#include "common/msg.h"
|
|
|
|
#include <mpg123.h>
|
|
|
|
#if (defined MPG123_API_VERSION) && (MPG123_API_VERSION < 33)
|
|
#error "This should not happen"
|
|
#endif
|
|
|
|
struct ad_mpg123_context {
|
|
mpg123_handle *handle;
|
|
int sample_size;
|
|
/* Running mean for bit rate, stream length estimation. */
|
|
float mean_rate;
|
|
unsigned int mean_count;
|
|
/* Time delay for updates. */
|
|
short delay;
|
|
/* If the stream is actually VBR. */
|
|
char vbr;
|
|
};
|
|
|
|
static void uninit(struct dec_audio *da)
|
|
{
|
|
struct ad_mpg123_context *con = da->priv;
|
|
|
|
mpg123_close(con->handle);
|
|
mpg123_delete(con->handle);
|
|
mpg123_exit();
|
|
}
|
|
|
|
/* This initializes libmpg123 and prepares the handle, including funky
|
|
* parameters. */
|
|
static int init(struct dec_audio *da, const char *decoder)
|
|
{
|
|
int err;
|
|
struct ad_mpg123_context *con;
|
|
/* Assumption: You always call preinit + init + uninit, on every file.
|
|
* But you stop at preinit in case it fails.
|
|
* If that is not true, one must ensure not to call mpg123_init / exit
|
|
* twice in a row. */
|
|
if (mpg123_init() != MPG123_OK)
|
|
return 0;
|
|
|
|
da->priv = talloc_zero(NULL, struct ad_mpg123_context);
|
|
con = da->priv;
|
|
/* Auto-choice of optimized decoder (first argument NULL). */
|
|
con->handle = mpg123_new(NULL, &err);
|
|
if (!con->handle)
|
|
goto bad_end;
|
|
|
|
/* Basic settings.
|
|
* Don't spill messages, enable better resync with non-seekable streams.
|
|
* Give both flags individually without error checking to keep going with
|
|
* old libmpg123. Generally, it is not fatal if the flags are not
|
|
* honored */
|
|
mpg123_param(con->handle, MPG123_ADD_FLAGS, MPG123_QUIET, 0.0);
|
|
/* Do not bail out on malformed streams at all.
|
|
* MPlayer does not handle a decoder throwing the towel on crappy input. */
|
|
mpg123_param(con->handle, MPG123_RESYNC_LIMIT, -1, 0.0);
|
|
|
|
/* Open decisions: Configure libmpg123 to force encoding (or stay open about
|
|
* library builds that support only float or int32 output), (de)configure
|
|
* gapless decoding (won't work with seeking in MPlayer, though).
|
|
* Don't forget to eventually enable ReplayGain/RVA support, too.
|
|
* Let's try to run with the default for now. */
|
|
|
|
/* That would produce floating point output.
|
|
* You can get 32 and 24 bit ints, even 8 bit via format matrix.
|
|
* If wanting a specific encoding here, configure format matrix and
|
|
* make sure it is in set_format(). */
|
|
/* mpg123_param(con->handle, MPG123_ADD_FLAGS, MPG123_FORCE_FLOAT, 0.); */
|
|
|
|
/* Example for RVA choice (available since libmpg123 1.0.0):
|
|
mpg123_param(con->handle, MPG123_RVA, MPG123_RVA_MIX, 0.0) */
|
|
|
|
/* Prevent funky automatic resampling.
|
|
* This way, we can be sure that one frame will never produce
|
|
* more than 1152 stereo samples.
|
|
* Background:
|
|
* Going to decode directly to the output buffer. It is important to have
|
|
* MPG123_AUTO_RESAMPLE disabled for the buffer size being an all-time
|
|
* limit.
|
|
* We need at least 1152 samples. dec_audio.c normally guarantees this. */
|
|
mpg123_param(con->handle, MPG123_REMOVE_FLAGS, MPG123_AUTO_RESAMPLE, 0.);
|
|
|
|
err = mpg123_open_feed(con->handle);
|
|
if (err != MPG123_OK)
|
|
goto bad_end;
|
|
|
|
return 1;
|
|
|
|
bad_end:
|
|
if (!con->handle) {
|
|
MP_ERR(da, "mpg123 preinit error: %s\n", mpg123_plain_strerror(err));
|
|
} else {
|
|
MP_ERR(da, "mpg123 preinit error: %s\n", mpg123_strerror(con->handle));
|
|
}
|
|
|
|
uninit(da);
|
|
return 0;
|
|
}
|
|
|
|
static int mpg123_format_to_af(int mpg123_encoding)
|
|
{
|
|
/* Without external force, mpg123 will always choose signed encoding,
|
|
* and non-16-bit only on builds that don't support it.
|
|
* Be reminded that it doesn't matter to the MPEG file what encoding
|
|
* is produced from it. */
|
|
switch (mpg123_encoding) {
|
|
case MPG123_ENC_SIGNED_8: return AF_FORMAT_S8;
|
|
case MPG123_ENC_SIGNED_16: return AF_FORMAT_S16;
|
|
case MPG123_ENC_SIGNED_32: return AF_FORMAT_S32;
|
|
case MPG123_ENC_FLOAT_32: return AF_FORMAT_FLOAT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Compute bitrate from frame size. */
|
|
static int compute_bitrate(struct mpg123_frameinfo *i)
|
|
{
|
|
static const int samples_per_frame[4][4] = {
|
|
{-1, 384, 1152, 1152}, /* MPEG 1 */
|
|
{-1, 384, 1152, 576}, /* MPEG 2 */
|
|
{-1, 384, 1152, 576}, /* MPEG 2.5 */
|
|
{-1, -1, -1, -1}, /* Unknown */
|
|
};
|
|
return (int) ((i->framesize + 4) * 8 * i->rate /
|
|
samples_per_frame[i->version][i->layer] + 0.5);
|
|
}
|
|
|
|
/* Update mean bitrate. This could be dropped if accurate time display
|
|
* on audio file playback is not desired. */
|
|
static void update_info(struct dec_audio *da)
|
|
{
|
|
struct ad_mpg123_context *con = da->priv;
|
|
struct mpg123_frameinfo finfo;
|
|
if (mpg123_info(con->handle, &finfo) != MPG123_OK)
|
|
return;
|
|
|
|
/* finfo.bitrate is expressed in kilobits */
|
|
const int bitrate = finfo.bitrate * 1000;
|
|
|
|
if (finfo.vbr != MPG123_CBR) {
|
|
if (--con->delay < 1) {
|
|
if (++con->mean_count > ((unsigned int) -1) / 2)
|
|
con->mean_count = ((unsigned int) -1) / 4;
|
|
|
|
/* Might not be numerically optimal, but works fine enough. */
|
|
con->mean_rate = ((con->mean_count - 1) * con->mean_rate +
|
|
bitrate) / con->mean_count;
|
|
da->bitrate = (int) (con->mean_rate + 0.5);
|
|
|
|
con->delay = 10;
|
|
}
|
|
} else {
|
|
da->bitrate = bitrate ? bitrate : compute_bitrate(&finfo);
|
|
con->delay = 1;
|
|
con->mean_rate = 0.;
|
|
con->mean_count = 0;
|
|
}
|
|
}
|
|
|
|
/* libmpg123 has a new format ready; query and store, return return value
|
|
of mpg123_getformat() */
|
|
static int set_format(struct dec_audio *da)
|
|
{
|
|
struct ad_mpg123_context *con = da->priv;
|
|
int ret;
|
|
long rate;
|
|
int channels;
|
|
int encoding;
|
|
ret = mpg123_getformat(con->handle, &rate, &channels, &encoding);
|
|
if (ret == MPG123_OK) {
|
|
mp_audio_set_num_channels(&da->decoded, channels);
|
|
da->decoded.rate = rate;
|
|
int af = mpg123_format_to_af(encoding);
|
|
if (!af) {
|
|
/* This means we got a funny custom build of libmpg123 that only supports an unknown format. */
|
|
MP_ERR(da, "Bad encoding from mpg123: %i.\n", encoding);
|
|
return MPG123_ERR;
|
|
}
|
|
mp_audio_set_format(&da->decoded, af);
|
|
con->sample_size = channels * af_fmt2bps(af);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int decode_packet(struct dec_audio *da)
|
|
{
|
|
struct ad_mpg123_context *con = da->priv;
|
|
int ret;
|
|
|
|
mp_audio_set_null_data(&da->decoded);
|
|
|
|
struct demux_packet *pkt;
|
|
if (demux_read_packet_async(da->header, &pkt) == 0)
|
|
return AD_WAIT;
|
|
if (!pkt)
|
|
return AD_EOF;
|
|
|
|
/* Next bytes from that presentation time. */
|
|
if (pkt->pts != MP_NOPTS_VALUE) {
|
|
da->pts = pkt->pts;
|
|
da->pts_offset = 0;
|
|
}
|
|
|
|
/* Have to use mpg123_feed() to avoid decoding here. */
|
|
ret = mpg123_feed(con->handle, pkt->buffer, pkt->len);
|
|
talloc_free(pkt);
|
|
|
|
if (ret != MPG123_OK)
|
|
goto mpg123_fail;
|
|
|
|
unsigned char *audio = NULL;
|
|
size_t bytes = 0;
|
|
ret = mpg123_decode_frame(con->handle, NULL, &audio, &bytes);
|
|
|
|
if (ret == MPG123_NEED_MORE)
|
|
return 0;
|
|
|
|
if (ret != MPG123_OK && ret != MPG123_DONE && ret != MPG123_NEW_FORMAT)
|
|
goto mpg123_fail;
|
|
|
|
ret = set_format(da);
|
|
if (ret != MPG123_OK)
|
|
goto mpg123_fail;
|
|
|
|
if (con->sample_size < 1) {
|
|
MP_ERR(da, "no sample size\n");
|
|
return AD_ERR;
|
|
}
|
|
|
|
int got_samples = bytes / con->sample_size;
|
|
da->decoded.planes[0] = audio;
|
|
da->decoded.samples = got_samples;
|
|
|
|
update_info(da);
|
|
return 0;
|
|
|
|
mpg123_fail:
|
|
MP_ERR(da, "mpg123 decoding error: %s\n", mpg123_strerror(con->handle));
|
|
return AD_ERR;
|
|
}
|
|
|
|
static int control(struct dec_audio *da, int cmd, void *arg)
|
|
{
|
|
struct ad_mpg123_context *con = da->priv;
|
|
|
|
switch (cmd) {
|
|
case ADCTRL_RESET:
|
|
mp_audio_set_null_data(&da->decoded);
|
|
mpg123_close(con->handle);
|
|
|
|
if (mpg123_open_feed(con->handle) != MPG123_OK) {
|
|
MP_ERR(da, "mpg123 failed to reopen stream: %s\n",
|
|
mpg123_strerror(con->handle));
|
|
return CONTROL_FALSE;
|
|
}
|
|
return CONTROL_TRUE;
|
|
}
|
|
return CONTROL_UNKNOWN;
|
|
}
|
|
|
|
static void add_decoders(struct mp_decoder_list *list)
|
|
{
|
|
mp_add_decoder(list, "mpg123", "mp3", "mp3",
|
|
"High-performance decoder using libmpg123");
|
|
}
|
|
|
|
const struct ad_functions ad_mpg123 = {
|
|
.name = "mpg123",
|
|
.add_decoders = add_decoders,
|
|
.init = init,
|
|
.uninit = uninit,
|
|
.control = control,
|
|
.decode_packet = decode_packet,
|
|
};
|