diff options
Diffstat (limited to 'audio/decode/ad_mpg123.c')
| -rw-r--r-- | audio/decode/ad_mpg123.c | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/audio/decode/ad_mpg123.c b/audio/decode/ad_mpg123.c new file mode 100644 index 0000000000..a3ce2cdcf6 --- /dev/null +++ b/audio/decode/ad_mpg123.c @@ -0,0 +1,489 @@ +/* + * MPEG 1.0/2.0/2.5 audio layer I, II, III decoding with libmpg123 + * + * Copyright (C) 2010-2012 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_internal.h" + +static const ad_info_t info = { + "MPEG 1.0/2.0/2.5 layers I, II, III", + "mpg123", + "Thomas Orgis", + "mpg123.org", + "High-performance decoder using libmpg123." +}; + +LIBAD_EXTERN(mpg123) + +/* Reducing the ifdeffery to two main variants: + * 1. most compatible to any libmpg123 version + * 2. fastest variant with recent libmpg123 (>=1.14) + * Running variant 2 on older libmpg123 versions may work in + * principle, but is not supported. + * So, please leave the check for MPG123_API_VERSION there, m-kay? + */ +#include <mpg123.h> + +/* Enable faster mode of operation with newer libmpg123, avoiding + * unnecessary memcpy() calls. */ +#if (defined MPG123_API_VERSION) && (MPG123_API_VERSION >= 33) +#define AD_MPG123_FRAMEWISE +#endif + +/* Switch for updating bitrate info of VBR files. Not essential. */ +#define AD_MPG123_MEAN_BITRATE + +/* Funny thing, that. I assume I shall use it for selecting mpg123 channels. + * Please correct me if I guessed wrong. */ +extern int fakemono; + +struct ad_mpg123_context { + mpg123_handle *handle; +#ifdef AD_MPG123_MEAN_BITRATE + /* Running mean for bit rate, stream length estimation. */ + float mean_rate; + unsigned int mean_count; + /* Time delay for updates. */ + short delay; +#endif + /* If the stream is actually VBR. */ + char vbr; +}; + +/* This initializes libmpg123 and prepares the handle, including funky + * parameters. */ +static int preinit(sh_audio_t *sh) +{ + int err, flag; + 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; + + sh->context = malloc(sizeof(struct ad_mpg123_context)); + con = sh->context; + /* Auto-choice of optimized decoder (first argument NULL). */ + con->handle = mpg123_new(NULL, &err); + if (!con->handle) + goto bad_end; + + /* Guessing here: Default value triggers forced upmix of mono to stereo. */ + flag = fakemono == 0 ? MPG123_FORCE_STEREO : + fakemono == 1 ? MPG123_MONO_LEFT : + fakemono == 2 ? MPG123_MONO_RIGHT : 0; + if (mpg123_param(con->handle, MPG123_ADD_FLAGS, flag, 0.0) != MPG123_OK) + 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. */ + /* 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) */ + +#ifdef AD_MPG123_FRAMEWISE + /* Prevent funky automatic resampling. + * This way, we can be sure that one frame will never produce + * more than 1152 stereo samples. */ + mpg123_param(con->handle, MPG123_REMOVE_FLAGS, MPG123_AUTO_RESAMPLE, 0.); +#else + /* Older mpg123 is vulnerable to concatenated streams when gapless cutting + * is enabled (will only play the jingle of a badly constructed radio + * stream). The versions using framewise decoding are fine with that. */ + mpg123_param(con->handle, MPG123_REMOVE_FLAGS, MPG123_GAPLESS, 0.); +#endif + + return 1; + + bad_end: + if (!con->handle) + mp_msg(MSGT_DECAUDIO, MSGL_ERR, "mpg123 preinit error: %s\n", + mpg123_plain_strerror(err)); + else + mp_msg(MSGT_DECAUDIO, MSGL_ERR, "mpg123 preinit error: %s\n", + mpg123_strerror(con->handle)); + + if (con->handle) + mpg123_delete(con->handle); + mpg123_exit(); + free(sh->context); + sh->context = NULL; + 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 * 0.001 / + samples_per_frame[i->version][i->layer] + 0.5); +} + +/* Opted against the header printout from old mp3lib, too much + * irrelevant info. This is modelled after the mpg123 app's + * standard output line. + * If more verbosity is demanded, one can add more detail and + * also throw in ID3v2 info which libmpg123 collects anyway. */ +static void print_header_compact(struct mpg123_frameinfo *i) +{ + static const char *smodes[5] = { + "stereo", "joint-stereo", "dual-channel", "mono", "invalid" + }; + static const char *layers[4] = { + "Unknown", "I", "II", "III" + }; + static const char *versions[4] = { + "1.0", "2.0", "2.5", "x.x" + }; + + mp_msg(MSGT_DECAUDIO, MSGL_V, "MPEG %s layer %s, ", + versions[i->version], layers[i->layer]); + switch (i->vbr) { + case MPG123_CBR: + if (i->bitrate) + mp_msg(MSGT_DECAUDIO, MSGL_V, "%d kbit/s", i->bitrate); + else + mp_msg(MSGT_DECAUDIO, MSGL_V, "%d kbit/s (free format)", + compute_bitrate(i)); + break; + case MPG123_VBR: + mp_msg(MSGT_DECAUDIO, MSGL_V, "VBR"); + break; + case MPG123_ABR: + mp_msg(MSGT_DECAUDIO, MSGL_V, "%d kbit/s ABR", i->abr_rate); + break; + default: + mp_msg(MSGT_DECAUDIO, MSGL_V, "???"); + } + mp_msg(MSGT_DECAUDIO, MSGL_V, ", %ld Hz %s\n", i->rate, + smodes[i->mode]); +} + +/* This tries to extract a requested amount of decoded data. + * Even when you request 0 bytes, it will feed enough input so that + * the decoder _could_ have delivered something. + * Returns byte count >= 0, -1 on error. + * + * Thoughts on exact pts keeping: + * We have to assume that MPEG frames are cut in pieces by packet boundaries. + * Also, it might be possible that the first packet does not contain enough + * data to ensure initial stream sync... or re-sync on erroneous streams. + * So we need something robust to relate the decoded byte count to the correct + * time stamp. This is tricky, though. From the outside, you cannot tell if, + * after having fed two packets until the first output arrives, one should + * start counting from the first packet's pts or the second packet's. + * So, let's just count from the last fed package's pts. If the packets are + * exactly cut to MPEG frames, this will cause one frame mismatch in the + * beginning (when mpg123 peeks ahead for the following header), but will + * be corrected with the third frame already. One might add special code to + * not increment the base pts past the first packet's after a resync before + * the first decoded bytes arrived. */ +static int decode_a_bit(sh_audio_t *sh, unsigned char *buf, int count) +{ + int ret = MPG123_OK; + int got = 0; + struct ad_mpg123_context *con = sh->context; + + /* There will be one MPG123_NEW_FORMAT message on first open. + * This will be handled in init(). */ + do { + size_t got_now = 0; + + /* Feed the decoder. This will only fire from the second round on. */ + if (ret == MPG123_NEED_MORE) { + int incount; + double pts; + unsigned char *inbuf; + /* Feed more input data. */ + incount = ds_get_packet_pts(sh->ds, &inbuf, &pts); + if (incount <= 0) + break; /* Apparently that's it. EOF. */ + + /* Next bytes from that presentation time. */ + if (pts != MP_NOPTS_VALUE) { + sh->pts = pts; + sh->pts_bytes = 0; + } + +#ifdef AD_MPG123_FRAMEWISE + /* Have to use mpg123_feed() to avoid decoding here. */ + ret = mpg123_feed(con->handle, inbuf, incount); +#else + /* Do not use mpg123_feed(), added in later libmpg123 versions. */ + ret = mpg123_decode(con->handle, inbuf, incount, NULL, 0, NULL); +#endif + if (ret == MPG123_ERR) + break; + } + /* Theoretically, mpg123 could return MPG123_DONE, so be prepared. + * Should not happen in our usage, but it is a valid return code. */ + else if (ret == MPG123_ERR || ret == MPG123_DONE) + break; + + /* Try to decode a bit. This is the return value that counts + * for the loop condition. */ +#ifdef AD_MPG123_FRAMEWISE + if (!buf) { /* fake call just for feeding to get format */ + ret = mpg123_getformat(con->handle, NULL, NULL, NULL); + } else { /* This is the decoding. One frame at a time. */ + ret = mpg123_replace_buffer(con->handle, buf, count); + if (ret == MPG123_OK) + ret = mpg123_decode_frame(con->handle, NULL, NULL, &got_now); + } +#else + ret = mpg123_decode(con->handle, NULL, 0, buf + got, count - got, + &got_now); +#endif + + got += got_now; + sh->pts_bytes += got_now; + +#ifdef AD_MPG123_FRAMEWISE + } while (ret == MPG123_NEED_MORE || (got == 0 && count != 0)); +#else + } while (ret == MPG123_NEED_MORE || got < count); +#endif + + if (ret == MPG123_ERR) { + mp_msg(MSGT_DECAUDIO, MSGL_ERR, "mpg123 decoding failed: %s\n", + mpg123_strerror(con->handle)); + mpg123_close(con->handle); + return -1; + } + + return got; +} + +/* Close, reopen stream. Feed data until we know the format of the stream. + * 1 on success, 0 on error */ +static int reopen_stream(sh_audio_t *sh) +{ + struct ad_mpg123_context *con = (struct ad_mpg123_context*) sh->context; + + mpg123_close(con->handle); + /* No resetting of the context: + * We do not want to loose the mean bitrate data. */ + + /* Open and make sure we have fed enough data to get stream properties. */ + if (MPG123_OK == mpg123_open_feed(con->handle) && + /* Feed data until mpg123 is ready (has found stream beginning). */ + !decode_a_bit(sh, NULL, 0)) { + return 1; + } else { + mp_msg(MSGT_DECAUDIO, MSGL_ERR, + "mpg123 failed to reopen stream: %s\n", + mpg123_strerror(con->handle)); + mpg123_close(con->handle); + return 0; + } +} + +/* Now we really start accessing some data and determining file format. + * Paranoia note: The mpg123_close() on errors is not really necessary, + * But it ensures that we don't accidentally continue decoding with a + * bad state (possibly interpreting the format badly or whatnot). */ +static int init(sh_audio_t *sh) +{ + long rate = 0; + int channels = 0; + int encoding = 0; + mpg123_id3v2 *v2; + struct mpg123_frameinfo finfo; + struct ad_mpg123_context *con = sh->context; + + /* We're open about any output format that libmpg123 will suggest. + * Note that a standard build will always default to 16 bit signed and + * the native sample rate of the file. */ + if (MPG123_OK == mpg123_format_all(con->handle) && + reopen_stream(sh) && + MPG123_OK == mpg123_getformat(con->handle, &rate, &channels, &encoding) && + /* Forbid the format to change later on. */ + MPG123_OK == mpg123_format_none(con->handle) && + MPG123_OK == mpg123_format(con->handle, rate, channels, encoding) && + /* Get MPEG header info. */ + MPG123_OK == mpg123_info(con->handle, &finfo) && + /* Since we queried format, mpg123 should have read past ID3v2 tags. + * We need to decide if printing of UTF-8 encoded text info is wanted. */ + MPG123_OK == mpg123_id3(con->handle, NULL, &v2)) { + /* If we are here, we passed all hurdles. Yay! Extract the info. */ + print_header_compact(&finfo); + /* Do we want to print out the UTF-8 Id3v2 info? + if (v2) + print_id3v2(v2); */ + + /* Have kb/s, want B/s + * For VBR, the first frame will be a bad estimate. */ + sh->i_bps = (finfo.bitrate ? finfo.bitrate : compute_bitrate(&finfo)) + * 1000 / 8; +#ifdef AD_MPG123_MEAN_BITRATE + con->delay = 1; + con->mean_rate = 0.; + con->mean_count = 0; +#endif + con->vbr = (finfo.vbr != MPG123_CBR); + sh->channels = channels; + sh->samplerate = rate; + /* 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 (encoding) { + case MPG123_ENC_SIGNED_8: + sh->sample_format = AF_FORMAT_S8; + sh->samplesize = 1; + break; + case MPG123_ENC_SIGNED_16: + sh->sample_format = AF_FORMAT_S16_NE; + sh->samplesize = 2; + break; + /* To stay compatible with the oldest libmpg123 headers, do not rely + * on float and 32 bit encoding symbols being defined. + * Those formats came later */ + case 0x1180: /* MPG123_ENC_SIGNED_32 */ + sh->sample_format = AF_FORMAT_S32_NE; + sh->samplesize = 4; + break; + case 0x200: /* MPG123_ENC_FLOAT_32 */ + sh->sample_format = AF_FORMAT_FLOAT_NE; + sh->samplesize = 4; + break; + default: + mp_msg(MSGT_DECAUDIO, MSGL_ERR, + "Bad encoding from mpg123: %i.\n", encoding); + mpg123_close(con->handle); + return 0; + } +#ifdef AD_MPG123_FRAMEWISE + /* Going to decode directly to MPlayer's memory. It is important + * to have MPG123_AUTO_RESAMPLE disabled for the buffer size + * being an all-time limit. */ + sh->audio_out_minsize = 1152 * 2 * sh->samplesize; +#endif + + return 1; + } else { + mp_msg(MSGT_DECAUDIO, MSGL_ERR, "mpg123 init error: %s\n", + mpg123_strerror(con->handle)); + mpg123_close(con->handle); + return 0; + } +} + +static void uninit(sh_audio_t *sh) +{ + struct ad_mpg123_context *con = (struct ad_mpg123_context*) sh->context; + + mpg123_close(con->handle); + mpg123_delete(con->handle); + free(sh->context); + sh->context = NULL; + mpg123_exit(); +} + +#ifdef AD_MPG123_MEAN_BITRATE +/* Update mean bitrate. This could be dropped if accurate time display + * on audio file playback is not desired. */ +static void update_info(sh_audio_t *sh) +{ + struct ad_mpg123_context *con = sh->context; + if (con->vbr && --con->delay < 1) { + struct mpg123_frameinfo finfo; + if (MPG123_OK == mpg123_info(con->handle, &finfo)) { + 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 + + finfo.bitrate) / con->mean_count; + sh->i_bps = (int) (con->mean_rate * 1000 / 8); + + con->delay = 10; + } + } +} +#endif + +static int decode_audio(sh_audio_t *sh, unsigned char *buf, int minlen, + int maxlen) +{ + int bytes; + + bytes = decode_a_bit(sh, buf, maxlen); + if (bytes == 0) + return -1; /* EOF */ + +#ifdef AD_MPG123_MEAN_BITRATE + update_info(sh); +#endif + return bytes; +} + +static int control(sh_audio_t *sh, int cmd, void *arg, ...) +{ + switch (cmd) { + case ADCTRL_RESYNC_STREAM: + /* Close/reopen the stream for mpg123 to make sure it doesn't + * think that it still knows the exact stream position. + * Otherwise, we would have funny effects from the gapless code. + * Oh, and it helps to minimize artifacts from jumping in the stream. */ + if (reopen_stream(sh)) { +#ifdef AD_MPG123_MEAN_BITRATE + update_info(sh); +#endif + return CONTROL_TRUE; + } else { + /* MPlayer ignores this case! It just keeps on decoding. + * So we have to make sure resync never fails ... */ + mp_msg(MSGT_DECAUDIO, MSGL_ERR, + "mpg123 cannot reopen stream for resync.\n"); + return CONTROL_FALSE; + } + break; + } + return CONTROL_UNKNOWN; +} |