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Diffstat (limited to 'src/decoder/MadDecoderPlugin.cxx')
| -rw-r--r-- | src/decoder/MadDecoderPlugin.cxx | 1186 |
1 files changed, 1186 insertions, 0 deletions
diff --git a/src/decoder/MadDecoderPlugin.cxx b/src/decoder/MadDecoderPlugin.cxx new file mode 100644 index 000000000..339fd5397 --- /dev/null +++ b/src/decoder/MadDecoderPlugin.cxx @@ -0,0 +1,1186 @@ +/* + * Copyright (C) 2003-2013 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program 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. + * + * This program 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 this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "config.h" +#include "MadDecoderPlugin.hxx" +#include "decoder_api.h" +#include "conf.h" + +extern "C" { +#include "tag_id3.h" +#include "tag_rva2.h" +} + +#include "tag_handler.h" +#include "audio_check.h" + +#include <assert.h> +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <glib.h> +#include <mad.h> + +#ifdef HAVE_ID3TAG +#include <id3tag.h> +#endif + +#undef G_LOG_DOMAIN +#define G_LOG_DOMAIN "mad" + +#define FRAMES_CUSHION 2000 + +#define READ_BUFFER_SIZE 40960 + +enum mp3_action { + DECODE_SKIP = -3, + DECODE_BREAK = -2, + DECODE_CONT = -1, + DECODE_OK = 0 +}; + +enum muteframe { + MUTEFRAME_NONE, + MUTEFRAME_SKIP, + MUTEFRAME_SEEK +}; + +/* the number of samples of silence the decoder inserts at start */ +#define DECODERDELAY 529 + +#define DEFAULT_GAPLESS_MP3_PLAYBACK true + +static bool gapless_playback; + +static inline int32_t +mad_fixed_to_24_sample(mad_fixed_t sample) +{ + enum { + bits = 24, + MIN = -MAD_F_ONE, + MAX = MAD_F_ONE - 1 + }; + + /* round */ + sample = sample + (1L << (MAD_F_FRACBITS - bits)); + + /* clip */ + if (gcc_unlikely(sample > MAX)) + sample = MAX; + else if (gcc_unlikely(sample < MIN)) + sample = MIN; + + /* quantize */ + return sample >> (MAD_F_FRACBITS + 1 - bits); +} + +static void +mad_fixed_to_24_buffer(int32_t *dest, const struct mad_synth *synth, + unsigned int start, unsigned int end, + unsigned int num_channels) +{ + unsigned int i, c; + + for (i = start; i < end; ++i) { + for (c = 0; c < num_channels; ++c) + *dest++ = mad_fixed_to_24_sample(synth->pcm.samples[c][i]); + } +} + +static bool +mp3_plugin_init(G_GNUC_UNUSED const struct config_param *param) +{ + gapless_playback = config_get_bool(CONF_GAPLESS_MP3_PLAYBACK, + DEFAULT_GAPLESS_MP3_PLAYBACK); + return true; +} + +#define MP3_DATA_OUTPUT_BUFFER_SIZE 2048 + +struct MadDecoder { + struct mad_stream stream; + struct mad_frame frame; + struct mad_synth synth; + mad_timer_t timer; + unsigned char input_buffer[READ_BUFFER_SIZE]; + int32_t output_buffer[MP3_DATA_OUTPUT_BUFFER_SIZE]; + float total_time; + float elapsed_time; + float seek_where; + enum muteframe mute_frame; + long *frame_offsets; + mad_timer_t *times; + unsigned long highest_frame; + unsigned long max_frames; + unsigned long current_frame; + unsigned int drop_start_frames; + unsigned int drop_end_frames; + unsigned int drop_start_samples; + unsigned int drop_end_samples; + bool found_replay_gain; + bool found_xing; + bool found_first_frame; + bool decoded_first_frame; + unsigned long bit_rate; + struct decoder *decoder; + struct input_stream *input_stream; + enum mad_layer layer; + + MadDecoder(struct decoder *decoder, struct input_stream *input_stream); + ~MadDecoder(); + + bool Seek(long offset); + bool FillBuffer(); + void ParseId3(size_t tagsize, struct tag **mpd_tag); + enum mp3_action DecodeNextFrameHeader(struct tag **tag); + enum mp3_action DecodeNextFrame(); + + gcc_pure + goffset ThisFrameOffset() const; + + gcc_pure + goffset RestIncludingThisFrame() const; + + /** + * Attempt to calulcate the length of the song from filesize + */ + void FileSizeToSongLength(); + + bool DecodeFirstFrame(struct tag **tag); + + gcc_pure + long TimeToFrame(double t) const; + + void UpdateTimerNextFrame(); + + /** + * Sends the synthesized current frame via decoder_data(). + */ + enum decoder_command SendPCM(unsigned i, unsigned pcm_length); + + /** + * Synthesize the current frame and send it via + * decoder_data(). + */ + enum decoder_command SyncAndSend(); + + bool Read(); +}; + +MadDecoder::MadDecoder(struct decoder *_decoder, + struct input_stream *_input_stream) + :mute_frame(MUTEFRAME_NONE), + frame_offsets(nullptr), + times(nullptr), + highest_frame(0), max_frames(0), current_frame(0), + drop_start_frames(0), drop_end_frames(0), + drop_start_samples(0), drop_end_samples(0), + found_replay_gain(false), found_xing(false), + found_first_frame(false), decoded_first_frame(false), + decoder(_decoder), input_stream(_input_stream), + layer(mad_layer(0)) +{ + mad_stream_init(&stream); + mad_stream_options(&stream, MAD_OPTION_IGNORECRC); + mad_frame_init(&frame); + mad_synth_init(&synth); + mad_timer_reset(&timer); +} + +inline bool +MadDecoder::Seek(long offset) +{ + if (!input_stream_lock_seek(input_stream, offset, SEEK_SET, + nullptr)) + return false; + + mad_stream_buffer(&stream, input_buffer, 0); + stream.error = MAD_ERROR_NONE; + + return true; +} + +inline bool +MadDecoder::FillBuffer() +{ + size_t remaining, length; + unsigned char *dest; + + if (stream.next_frame != nullptr) { + remaining = stream.bufend - stream.next_frame; + memmove(input_buffer, stream.next_frame, remaining); + dest = input_buffer + remaining; + length = READ_BUFFER_SIZE - remaining; + } else { + remaining = 0; + length = READ_BUFFER_SIZE; + dest = input_buffer; + } + + /* we've exhausted the read buffer, so give up!, these potential + * mp3 frames are way too big, and thus unlikely to be mp3 frames */ + if (length == 0) + return false; + + length = decoder_read(decoder, input_stream, dest, length); + if (length == 0) + return false; + + mad_stream_buffer(&stream, input_buffer, length + remaining); + stream.error = MAD_ERROR_NONE; + + return true; +} + +#ifdef HAVE_ID3TAG +static bool +parse_id3_replay_gain_info(struct replay_gain_info *replay_gain_info, + struct id3_tag *tag) +{ + int i; + char *key; + char *value; + struct id3_frame *frame; + bool found = false; + + replay_gain_info_init(replay_gain_info); + + for (i = 0; (frame = id3_tag_findframe(tag, "TXXX", i)); i++) { + if (frame->nfields < 3) + continue; + + key = (char *) + id3_ucs4_latin1duplicate(id3_field_getstring + (&frame->fields[1])); + value = (char *) + id3_ucs4_latin1duplicate(id3_field_getstring + (&frame->fields[2])); + + if (g_ascii_strcasecmp(key, "replaygain_track_gain") == 0) { + replay_gain_info->tuples[REPLAY_GAIN_TRACK].gain = atof(value); + found = true; + } else if (g_ascii_strcasecmp(key, "replaygain_album_gain") == 0) { + replay_gain_info->tuples[REPLAY_GAIN_ALBUM].gain = atof(value); + found = true; + } else if (g_ascii_strcasecmp(key, "replaygain_track_peak") == 0) { + replay_gain_info->tuples[REPLAY_GAIN_TRACK].peak = atof(value); + found = true; + } else if (g_ascii_strcasecmp(key, "replaygain_album_peak") == 0) { + replay_gain_info->tuples[REPLAY_GAIN_ALBUM].peak = atof(value); + found = true; + } + + free(key); + free(value); + } + + return found || + /* fall back on RVA2 if no replaygain tags found */ + tag_rva2_parse(tag, replay_gain_info); +} +#endif + +#ifdef HAVE_ID3TAG +static bool +parse_id3_mixramp(char **mixramp_start, char **mixramp_end, + struct id3_tag *tag) +{ + int i; + char *key; + char *value; + struct id3_frame *frame; + bool found = false; + + *mixramp_start = nullptr; + *mixramp_end = nullptr; + + for (i = 0; (frame = id3_tag_findframe(tag, "TXXX", i)); i++) { + if (frame->nfields < 3) + continue; + + key = (char *) + id3_ucs4_latin1duplicate(id3_field_getstring + (&frame->fields[1])); + value = (char *) + id3_ucs4_latin1duplicate(id3_field_getstring + (&frame->fields[2])); + + if (g_ascii_strcasecmp(key, "mixramp_start") == 0) { + *mixramp_start = g_strdup(value); + found = true; + } else if (g_ascii_strcasecmp(key, "mixramp_end") == 0) { + *mixramp_end = g_strdup(value); + found = true; + } + + free(key); + free(value); + } + + return found; +} +#endif + +inline void +MadDecoder::ParseId3(size_t tagsize, struct tag **mpd_tag) +{ +#ifdef HAVE_ID3TAG + struct id3_tag *id3_tag = nullptr; + id3_length_t count; + id3_byte_t const *id3_data; + id3_byte_t *allocated = nullptr; + + count = stream.bufend - stream.this_frame; + + if (tagsize <= count) { + id3_data = stream.this_frame; + mad_stream_skip(&(stream), tagsize); + } else { + allocated = (id3_byte_t *)g_malloc(tagsize); + memcpy(allocated, stream.this_frame, count); + mad_stream_skip(&(stream), count); + + while (count < tagsize) { + size_t len; + + len = decoder_read(decoder, input_stream, + allocated + count, tagsize - count); + if (len == 0) + break; + else + count += len; + } + + if (count != tagsize) { + g_debug("error parsing ID3 tag"); + g_free(allocated); + return; + } + + id3_data = allocated; + } + + id3_tag = id3_tag_parse(id3_data, tagsize); + if (id3_tag == nullptr) { + g_free(allocated); + return; + } + + if (mpd_tag) { + struct tag *tmp_tag = tag_id3_import(id3_tag); + if (tmp_tag != nullptr) { + if (*mpd_tag != nullptr) + tag_free(*mpd_tag); + *mpd_tag = tmp_tag; + } + } + + if (decoder != nullptr) { + struct replay_gain_info rgi; + char *mixramp_start; + char *mixramp_end; + + if (parse_id3_replay_gain_info(&rgi, id3_tag)) { + decoder_replay_gain(decoder, &rgi); + found_replay_gain = true; + } + + if (parse_id3_mixramp(&mixramp_start, &mixramp_end, id3_tag)) + decoder_mixramp(decoder, mixramp_start, mixramp_end); + } + + id3_tag_delete(id3_tag); + + g_free(allocated); +#else /* !HAVE_ID3TAG */ + (void)mpd_tag; + + /* This code is enabled when libid3tag is disabled. Instead + of parsing the ID3 frame, it just skips it. */ + + size_t count = stream.bufend - stream.this_frame; + + if (tagsize <= count) { + mad_stream_skip(&stream, tagsize); + } else { + mad_stream_skip(&stream, count); + + while (count < tagsize) { + size_t len = tagsize - count; + char ignored[1024]; + if (len > sizeof(ignored)) + len = sizeof(ignored); + + len = decoder_read(decoder, input_stream, + ignored, len); + if (len == 0) + break; + else + count += len; + } + } +#endif +} + +#ifndef HAVE_ID3TAG +/** + * This function emulates libid3tag when it is disabled. Instead of + * doing a real analyzation of the frame, it just checks whether the + * frame begins with the string "ID3". If so, it returns the length + * of the ID3 frame. + */ +static signed long +id3_tag_query(const void *p0, size_t length) +{ + const char *p = (const char *)p0; + + return length >= 10 && memcmp(p, "ID3", 3) == 0 + ? (p[8] << 7) + p[9] + 10 + : 0; +} +#endif /* !HAVE_ID3TAG */ + +enum mp3_action +MadDecoder::DecodeNextFrameHeader(struct tag **tag) +{ + if ((stream.buffer == nullptr || stream.error == MAD_ERROR_BUFLEN) && + !FillBuffer()) + return DECODE_BREAK; + + if (mad_header_decode(&frame.header, &stream)) { + if (stream.error == MAD_ERROR_LOSTSYNC && stream.this_frame) { + signed long tagsize = id3_tag_query(stream.this_frame, + stream.bufend - + stream.this_frame); + + if (tagsize > 0) { + if (tag && !(*tag)) { + ParseId3((size_t)tagsize, tag); + } else { + mad_stream_skip(&stream, tagsize); + } + return DECODE_CONT; + } + } + if (MAD_RECOVERABLE(stream.error)) { + return DECODE_SKIP; + } else { + if (stream.error == MAD_ERROR_BUFLEN) + return DECODE_CONT; + else { + g_warning("unrecoverable frame level error " + "(%s).\n", + mad_stream_errorstr(&stream)); + return DECODE_BREAK; + } + } + } + + enum mad_layer new_layer = frame.header.layer; + if (layer == (mad_layer)0) { + if (new_layer != MAD_LAYER_II && new_layer != MAD_LAYER_III) { + /* Only layer 2 and 3 have been tested to work */ + return DECODE_SKIP; + } + + layer = new_layer; + } else if (new_layer != layer) { + /* Don't decode frames with a different layer than the first */ + return DECODE_SKIP; + } + + return DECODE_OK; +} + +enum mp3_action +MadDecoder::DecodeNextFrame() +{ + if ((stream.buffer == nullptr || stream.error == MAD_ERROR_BUFLEN) && + !FillBuffer()) + return DECODE_BREAK; + + if (mad_frame_decode(&frame, &stream)) { + if (stream.error == MAD_ERROR_LOSTSYNC) { + signed long tagsize = id3_tag_query(stream.this_frame, + stream.bufend - + stream.this_frame); + if (tagsize > 0) { + mad_stream_skip(&stream, tagsize); + return DECODE_CONT; + } + } + if (MAD_RECOVERABLE(stream.error)) { + return DECODE_SKIP; + } else { + if (stream.error == MAD_ERROR_BUFLEN) + return DECODE_CONT; + else { + g_warning("unrecoverable frame level error " + "(%s).\n", + mad_stream_errorstr(&stream)); + return DECODE_BREAK; + } + } + } + + return DECODE_OK; +} + +/* xing stuff stolen from alsaplayer, and heavily modified by jat */ +#define XI_MAGIC (('X' << 8) | 'i') +#define NG_MAGIC (('n' << 8) | 'g') +#define IN_MAGIC (('I' << 8) | 'n') +#define FO_MAGIC (('f' << 8) | 'o') + +enum xing_magic { + XING_MAGIC_XING, /* VBR */ + XING_MAGIC_INFO /* CBR */ +}; + +struct xing { + long flags; /* valid fields (see below) */ + unsigned long frames; /* total number of frames */ + unsigned long bytes; /* total number of bytes */ + unsigned char toc[100]; /* 100-point seek table */ + long scale; /* VBR quality */ + enum xing_magic magic; /* header magic */ +}; + +enum { + XING_FRAMES = 0x00000001L, + XING_BYTES = 0x00000002L, + XING_TOC = 0x00000004L, + XING_SCALE = 0x00000008L +}; + +struct lame_version { + unsigned major; + unsigned minor; +}; + +struct lame { + char encoder[10]; /* 9 byte encoder name/version ("LAME3.97b") */ + struct lame_version version; /* struct containing just the version */ + float peak; /* replaygain peak */ + float track_gain; /* replaygain track gain */ + float album_gain; /* replaygain album gain */ + int encoder_delay; /* # of added samples at start of mp3 */ + int encoder_padding; /* # of added samples at end of mp3 */ + int crc; /* CRC of the first 190 bytes of this frame */ +}; + +static bool +parse_xing(struct xing *xing, struct mad_bitptr *ptr, int *oldbitlen) +{ + unsigned long bits; + int bitlen; + int bitsleft; + int i; + + bitlen = *oldbitlen; + + if (bitlen < 16) + return false; + + bits = mad_bit_read(ptr, 16); + bitlen -= 16; + + if (bits == XI_MAGIC) { + if (bitlen < 16) + return false; + + if (mad_bit_read(ptr, 16) != NG_MAGIC) + return false; + + bitlen -= 16; + xing->magic = XING_MAGIC_XING; + } else if (bits == IN_MAGIC) { + if (bitlen < 16) + return false; + + if (mad_bit_read(ptr, 16) != FO_MAGIC) + return false; + + bitlen -= 16; + xing->magic = XING_MAGIC_INFO; + } + else if (bits == NG_MAGIC) xing->magic = XING_MAGIC_XING; + else if (bits == FO_MAGIC) xing->magic = XING_MAGIC_INFO; + else + return false; + + if (bitlen < 32) + return false; + xing->flags = mad_bit_read(ptr, 32); + bitlen -= 32; + + if (xing->flags & XING_FRAMES) { + if (bitlen < 32) + return false; + xing->frames = mad_bit_read(ptr, 32); + bitlen -= 32; + } + + if (xing->flags & XING_BYTES) { + if (bitlen < 32) + return false; + xing->bytes = mad_bit_read(ptr, 32); + bitlen -= 32; + } + + if (xing->flags & XING_TOC) { + if (bitlen < 800) + return false; + for (i = 0; i < 100; ++i) xing->toc[i] = mad_bit_read(ptr, 8); + bitlen -= 800; + } + + if (xing->flags & XING_SCALE) { + if (bitlen < 32) + return false; + xing->scale = mad_bit_read(ptr, 32); + bitlen -= 32; + } + + /* Make sure we consume no less than 120 bytes (960 bits) in hopes that + * the LAME tag is found there, and not right after the Xing header */ + bitsleft = 960 - ((*oldbitlen) - bitlen); + if (bitsleft < 0) + return false; + else if (bitsleft > 0) { + mad_bit_read(ptr, bitsleft); + bitlen -= bitsleft; + } + + *oldbitlen = bitlen; + + return true; +} + +static bool +parse_lame(struct lame *lame, struct mad_bitptr *ptr, int *bitlen) +{ + int adj = 0; + int name; + int orig; + int sign; + int gain; + int i; + + /* Unlike the xing header, the lame tag has a fixed length. Fail if + * not all 36 bytes (288 bits) are there. */ + if (*bitlen < 288) + return false; + + for (i = 0; i < 9; i++) + lame->encoder[i] = (char)mad_bit_read(ptr, 8); + lame->encoder[9] = '\0'; + + *bitlen -= 72; + + /* This is technically incorrect, since the encoder might not be lame. + * But there's no other way to determine if this is a lame tag, and we + * wouldn't want to go reading a tag that's not there. */ + if (!g_str_has_prefix(lame->encoder, "LAME")) + return false; + + if (sscanf(lame->encoder+4, "%u.%u", + &lame->version.major, &lame->version.minor) != 2) + return false; + + g_debug("detected LAME version %i.%i (\"%s\")\n", + lame->version.major, lame->version.minor, lame->encoder); + + /* The reference volume was changed from the 83dB used in the + * ReplayGain spec to 89dB in lame 3.95.1. Bump the gain for older + * versions, since everyone else uses 89dB instead of 83dB. + * Unfortunately, lame didn't differentiate between 3.95 and 3.95.1, so + * it's impossible to make the proper adjustment for 3.95. + * Fortunately, 3.95 was only out for about a day before 3.95.1 was + * released. -- tmz */ + if (lame->version.major < 3 || + (lame->version.major == 3 && lame->version.minor < 95)) + adj = 6; + + mad_bit_read(ptr, 16); + + lame->peak = mad_f_todouble(mad_bit_read(ptr, 32) << 5); /* peak */ + g_debug("LAME peak found: %f\n", lame->peak); + + lame->track_gain = 0; + name = mad_bit_read(ptr, 3); /* gain name */ + orig = mad_bit_read(ptr, 3); /* gain originator */ + sign = mad_bit_read(ptr, 1); /* sign bit */ + gain = mad_bit_read(ptr, 9); /* gain*10 */ + if (gain && name == 1 && orig != 0) { + lame->track_gain = ((sign ? -gain : gain) / 10.0) + adj; + g_debug("LAME track gain found: %f\n", lame->track_gain); + } + + /* tmz reports that this isn't currently written by any version of lame + * (as of 3.97). Since we have no way of testing it, don't use it. + * Wouldn't want to go blowing someone's ears just because we read it + * wrong. :P -- jat */ + lame->album_gain = 0; +#if 0 + name = mad_bit_read(ptr, 3); /* gain name */ + orig = mad_bit_read(ptr, 3); /* gain originator */ + sign = mad_bit_read(ptr, 1); /* sign bit */ + gain = mad_bit_read(ptr, 9); /* gain*10 */ + if (gain && name == 2 && orig != 0) { + lame->album_gain = ((sign ? -gain : gain) / 10.0) + adj; + g_debug("LAME album gain found: %f\n", lame->track_gain); + } +#else + mad_bit_read(ptr, 16); +#endif + + mad_bit_read(ptr, 16); + + lame->encoder_delay = mad_bit_read(ptr, 12); + lame->encoder_padding = mad_bit_read(ptr, 12); + + g_debug("encoder delay is %i, encoder padding is %i\n", + lame->encoder_delay, lame->encoder_padding); + + mad_bit_read(ptr, 80); + + lame->crc = mad_bit_read(ptr, 16); + + *bitlen -= 216; + + return true; +} + +static inline float +mp3_frame_duration(const struct mad_frame *frame) +{ + return mad_timer_count(frame->header.duration, + MAD_UNITS_MILLISECONDS) / 1000.0; +} + +inline goffset +MadDecoder::ThisFrameOffset() const +{ + goffset offset = input_stream_get_offset(input_stream); + + if (stream.this_frame != nullptr) + offset -= stream.bufend - stream.this_frame; + else + offset -= stream.bufend - stream.buffer; + + return offset; +} + +inline goffset +MadDecoder::RestIncludingThisFrame() const +{ + return input_stream_get_size(input_stream) - ThisFrameOffset(); +} + +inline void +MadDecoder::FileSizeToSongLength() +{ + goffset rest = RestIncludingThisFrame(); + + if (rest > 0) { + float frame_duration = mp3_frame_duration(&frame); + + total_time = (rest * 8.0) / frame.header.bitrate; + max_frames = total_time / frame_duration + FRAMES_CUSHION; + } else { + max_frames = FRAMES_CUSHION; + total_time = 0; + } +} + +inline bool +MadDecoder::DecodeFirstFrame(struct tag **tag) +{ + struct xing xing; + struct lame lame; + struct mad_bitptr ptr; + int bitlen; + enum mp3_action ret; + + /* stfu gcc */ + memset(&xing, 0, sizeof(struct xing)); + xing.flags = 0; + + while (true) { + do { + ret = DecodeNextFrameHeader(tag); + } while (ret == DECODE_CONT); + if (ret == DECODE_BREAK) + return false; + if (ret == DECODE_SKIP) continue; + + do { + ret = DecodeNextFrame(); + } while (ret == DECODE_CONT); + if (ret == DECODE_BREAK) + return false; + if (ret == DECODE_OK) break; + } + + ptr = stream.anc_ptr; + bitlen = stream.anc_bitlen; + + FileSizeToSongLength(); + + /* + * if an xing tag exists, use that! + */ + if (parse_xing(&xing, &ptr, &bitlen)) { + found_xing = true; + mute_frame = MUTEFRAME_SKIP; + + if ((xing.flags & XING_FRAMES) && xing.frames) { + mad_timer_t duration = frame.header.duration; + mad_timer_multiply(&duration, xing.frames); + total_time = ((float)mad_timer_count(duration, MAD_UNITS_MILLISECONDS)) / 1000; + max_frames = xing.frames; + } + + if (parse_lame(&lame, &ptr, &bitlen)) { + if (gapless_playback && + input_stream_is_seekable(input_stream)) { + drop_start_samples = lame.encoder_delay + + DECODERDELAY; + drop_end_samples = lame.encoder_padding; + } + + /* Album gain isn't currently used. See comment in + * parse_lame() for details. -- jat */ + if (decoder != nullptr && !found_replay_gain && + lame.track_gain) { + struct replay_gain_info rgi; + replay_gain_info_init(&rgi); + rgi.tuples[REPLAY_GAIN_TRACK].gain = lame.track_gain; + rgi.tuples[REPLAY_GAIN_TRACK].peak = lame.peak; + decoder_replay_gain(decoder, &rgi); + } + } + } + + if (!max_frames) + return false; + + if (max_frames > 8 * 1024 * 1024) { + g_warning("mp3 file header indicates too many frames: %lu\n", + max_frames); + return false; + } + + frame_offsets = new long[max_frames]; + times = new mad_timer_t[max_frames]; + + return true; +} + +MadDecoder::~MadDecoder() +{ + mad_synth_finish(&synth); + mad_frame_finish(&frame); + mad_stream_finish(&stream); + + delete[] frame_offsets; + delete[] times; +} + +/* this is primarily used for getting total time for tags */ +static int +mad_decoder_total_file_time(struct input_stream *is) +{ + MadDecoder data(nullptr, is); + return data.DecodeFirstFrame(nullptr) + ? data.total_time + 0.5 + : -1; +} + +long +MadDecoder::TimeToFrame(double t) const +{ + unsigned long i; + + for (i = 0; i < highest_frame; ++i) { + double frame_time = + mad_timer_count(times[i], + MAD_UNITS_MILLISECONDS) / 1000.; + if (frame_time >= t) + break; + } + + return i; +} + +void +MadDecoder::UpdateTimerNextFrame() +{ + if (current_frame >= highest_frame) { + /* record this frame's properties in frame_offsets + (for seeking) and times */ + bit_rate = frame.header.bitrate; + + if (current_frame >= max_frames) + /* cap current_frame */ + current_frame = max_frames - 1; + else + highest_frame++; + + frame_offsets[current_frame] = ThisFrameOffset(); + + mad_timer_add(&timer, frame.header.duration); + times[current_frame] = timer; + } else + /* get the new timer value from "times" */ + timer = times[current_frame]; + + current_frame++; + elapsed_time = mad_timer_count(timer, MAD_UNITS_MILLISECONDS) / 1000.0; +} + +enum decoder_command +MadDecoder::SendPCM(unsigned i, unsigned pcm_length) +{ + unsigned max_samples; + + max_samples = sizeof(output_buffer) / + sizeof(output_buffer[0]) / + MAD_NCHANNELS(&frame.header); + + while (i < pcm_length) { + enum decoder_command cmd; + unsigned int num_samples = pcm_length - i; + if (num_samples > max_samples) + num_samples = max_samples; + + i += num_samples; + + mad_fixed_to_24_buffer(output_buffer, &synth, + i - num_samples, i, + MAD_NCHANNELS(&frame.header)); + num_samples *= MAD_NCHANNELS(&frame.header); + + cmd = decoder_data(decoder, input_stream, output_buffer, + sizeof(output_buffer[0]) * num_samples, + bit_rate / 1000); + if (cmd != DECODE_COMMAND_NONE) + return cmd; + } + + return DECODE_COMMAND_NONE; +} + +inline enum decoder_command +MadDecoder::SyncAndSend() +{ + mad_synth_frame(&synth, &frame); + + if (!found_first_frame) { + unsigned int samples_per_frame = synth.pcm.length; + drop_start_frames = drop_start_samples / samples_per_frame; + drop_end_frames = drop_end_samples / samples_per_frame; + drop_start_samples = drop_start_samples % samples_per_frame; + drop_end_samples = drop_end_samples % samples_per_frame; + found_first_frame = true; + } + + if (drop_start_frames > 0) { + drop_start_frames--; + return DECODE_COMMAND_NONE; + } else if ((drop_end_frames > 0) && + (current_frame == (max_frames + 1 - drop_end_frames))) { + /* stop decoding, effectively dropping all remaining + frames */ + return DECODE_COMMAND_STOP; + } + + unsigned i = 0; + if (!decoded_first_frame) { + i = drop_start_samples; + decoded_first_frame = true; + } + + unsigned pcm_length = synth.pcm.length; + if (drop_end_samples && + (current_frame == max_frames - drop_end_frames)) { + if (drop_end_samples >= pcm_length) + pcm_length = 0; + else + pcm_length -= drop_end_samples; + } + + enum decoder_command cmd = SendPCM(i, pcm_length); + if (cmd != DECODE_COMMAND_NONE) + return cmd; + + if (drop_end_samples && + (current_frame == max_frames - drop_end_frames)) + /* stop decoding, effectively dropping + * all remaining samples */ + return DECODE_COMMAND_STOP; + + return DECODE_COMMAND_NONE; +} + +inline bool +MadDecoder::Read() +{ + enum mp3_action ret; + enum decoder_command cmd; + + UpdateTimerNextFrame(); + + switch (mute_frame) { + case MUTEFRAME_SKIP: + mute_frame = MUTEFRAME_NONE; + break; + case MUTEFRAME_SEEK: + if (elapsed_time >= seek_where) + mute_frame = MUTEFRAME_NONE; + break; + case MUTEFRAME_NONE: + cmd = SyncAndSend(); + if (cmd == DECODE_COMMAND_SEEK) { + unsigned long j; + + assert(input_stream_is_seekable(input_stream)); + + j = TimeToFrame(decoder_seek_where(decoder)); + if (j < highest_frame) { + if (Seek(frame_offsets[j])) { + current_frame = j; + decoder_command_finished(decoder); + } else + decoder_seek_error(decoder); + } else { + seek_where = decoder_seek_where(decoder); + mute_frame = MUTEFRAME_SEEK; + decoder_command_finished(decoder); + } + } else if (cmd != DECODE_COMMAND_NONE) + return false; + } + + while (true) { + bool skip = false; + + do { + struct tag *tag = nullptr; + + ret = DecodeNextFrameHeader(&tag); + + if (tag != nullptr) { + decoder_tag(decoder, input_stream, tag); + tag_free(tag); + } + } while (ret == DECODE_CONT); + if (ret == DECODE_BREAK) + return false; + else if (ret == DECODE_SKIP) + skip = true; + + if (mute_frame == MUTEFRAME_NONE) { + do { + ret = DecodeNextFrame(); + } while (ret == DECODE_CONT); + if (ret == DECODE_BREAK) + return false; + } + + if (!skip && ret == DECODE_OK) + break; + } + + return ret != DECODE_BREAK; +} + +static void +mp3_decode(struct decoder *decoder, struct input_stream *input_stream) +{ + MadDecoder data(decoder, input_stream); + + struct tag *tag = nullptr; + if (!data.DecodeFirstFrame(&tag)) { + if (tag != nullptr) + tag_free(tag); + + if (decoder_get_command(decoder) == DECODE_COMMAND_NONE) + g_warning + ("Input does not appear to be a mp3 bit stream.\n"); + return; + } + + struct audio_format audio_format; + GError *error = nullptr; + if (!audio_format_init_checked(&audio_format, + data.frame.header.samplerate, + SAMPLE_FORMAT_S24_P32, + MAD_NCHANNELS(&data.frame.header), + &error)) { + g_warning("%s", error->message); + g_error_free(error); + + if (tag != nullptr) + tag_free(tag); + return; + } + + decoder_initialized(decoder, &audio_format, + input_stream_is_seekable(input_stream), + data.total_time); + + if (tag != nullptr) { + decoder_tag(decoder, input_stream, tag); + tag_free(tag); + } + + while (data.Read()) {} +} + +static bool +mad_decoder_scan_stream(struct input_stream *is, + const struct tag_handler *handler, void *handler_ctx) +{ + int total_time; + + total_time = mad_decoder_total_file_time(is); + if (total_time < 0) + return false; + + tag_handler_invoke_duration(handler, handler_ctx, total_time); + return true; +} + +static const char *const mp3_suffixes[] = { "mp3", "mp2", nullptr }; +static const char *const mp3_mime_types[] = { "audio/mpeg", nullptr }; + +const struct decoder_plugin mad_decoder_plugin = { + "mad", + mp3_plugin_init, + nullptr, + mp3_decode, + nullptr, + nullptr, + mad_decoder_scan_stream, + nullptr, + mp3_suffixes, + mp3_mime_types, +}; |