diff options
Diffstat (limited to 'src/replay_gain.c')
| -rw-r--r-- | src/replay_gain.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/replay_gain.c b/src/replay_gain.c new file mode 100644 index 000000000..094c1c4f7 --- /dev/null +++ b/src/replay_gain.c @@ -0,0 +1,167 @@ +/* the Music Player Daemon (MPD) + * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com) + * (c)2004 replayGain code by AliasMrJones + * This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "replay_gain.h" +#include "utils.h" + +#include "log.h" +#include "conf.h" +#include "audio_format.h" +#include "os_compat.h" + +/* Added 4/14/2004 by AliasMrJones */ +int replayGainState = REPLAYGAIN_OFF; + +static float replayGainPreamp = 1.0; + +void initReplayGainState(void) +{ + ConfigParam *param = getConfigParam(CONF_REPLAYGAIN); + + if (!param) + return; + + if (strcmp(param->value, "track") == 0) { + replayGainState = REPLAYGAIN_TRACK; + } else if (strcmp(param->value, "album") == 0) { + replayGainState = REPLAYGAIN_ALBUM; + } else { + FATAL("replaygain value \"%s\" at line %i is invalid\n", + param->value, param->line); + } + + param = getConfigParam(CONF_REPLAYGAIN_PREAMP); + + if (param) { + char *test; + float f = strtod(param->value, &test); + + if (*test != '\0') { + FATAL("Replaygain preamp \"%s\" is not a number at " + "line %i\n", param->value, param->line); + } + + if (f < -15 || f > 15) { + FATAL("Replaygain preamp \"%s\" is not between -15 and" + "15 at line %i\n", param->value, param->line); + } + + replayGainPreamp = pow(10, f / 20.0); + } +} + +static float computeReplayGainScale(float gain, float peak) +{ + float scale; + + if (gain == 0.0) + return (1); + scale = pow(10.0, gain / 20.0); + scale *= replayGainPreamp; + if (scale > 15.0) + scale = 15.0; + + if (scale * peak > 1.0) { + scale = 1.0 / peak; + } + return (scale); +} + +ReplayGainInfo *newReplayGainInfo(void) +{ + ReplayGainInfo *ret = xmalloc(sizeof(ReplayGainInfo)); + + ret->albumGain = 0.0; + ret->albumPeak = 0.0; + + ret->trackGain = 0.0; + ret->trackPeak = 0.0; + + /* set to -1 so that we know in doReplayGain to compute the scale */ + ret->scale = -1.0; + + return ret; +} + +void freeReplayGainInfo(ReplayGainInfo * info) +{ + free(info); +} + +void doReplayGain(ReplayGainInfo * info, char *buffer, int bufferSize, + const struct audio_format *format) +{ + int16_t *buffer16; + int8_t *buffer8; + int32_t temp32; + float scale; + + if (replayGainState == REPLAYGAIN_OFF || !info) + return; + + if (info->scale < 0) { + switch (replayGainState) { + case REPLAYGAIN_TRACK: + DEBUG("computing ReplayGain track scale with gain %f, " + "peak %f\n", info->trackGain, info->trackPeak); + info->scale = computeReplayGainScale(info->trackGain, + info->trackPeak); + break; + default: + DEBUG("computing ReplayGain album scale with gain %f, " + "peak %f\n", info->albumGain, info->albumPeak); + info->scale = computeReplayGainScale(info->albumGain, + info->albumPeak); + break; + } + } + + if (info->scale <= 1.01 && info->scale >= 0.99) + return; + + buffer16 = (int16_t *) buffer; + buffer8 = (int8_t *) buffer; + + scale = info->scale; + + switch (format->bits) { + case 16: + while (bufferSize > 0) { + temp32 = *buffer16; + temp32 *= scale; + *buffer16 = temp32 > 32767 ? 32767 : + (temp32 < -32768 ? -32768 : temp32); + buffer16++; + bufferSize -= 2; + } + break; + case 8: + while (bufferSize > 0) { + temp32 = *buffer8; + temp32 *= scale; + *buffer8 = temp32 > 127 ? 127 : + (temp32 < -128 ? -128 : temp32); + buffer8++; + bufferSize--; + } + break; + default: + ERROR("%i bits not supported by doReplaygain!\n", format->bits); + } +} |