/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2005 Dave Chapman * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include "codeclib.h" #include #include CODEC_HEADER struct mad_stream stream IBSS_ATTR; struct mad_frame frame IBSS_ATTR; struct mad_synth synth IBSS_ATTR; /* The following function is used inside libmad - let's hope it's never called. */ void abort(void) { } #define INPUT_CHUNK_SIZE 8192 mad_fixed_t mad_frame_overlap[2][32][18] IBSS_ATTR; unsigned char mad_main_data[MAD_BUFFER_MDLEN] IBSS_ATTR; /* TODO: what latency does layer 1 have? */ int mpeg_latency[3] = { 0, 481, 529 }; #ifdef USE_IRAM extern char iramcopy[]; extern char iramstart[]; extern char iramend[]; extern char iedata[]; extern char iend[]; #endif struct codec_api *ci; int64_t samplecount; int64_t samplesdone; int stop_skip, start_skip; int current_stereo_mode = -1; unsigned long current_frequency = 0; void recalc_samplecount(void) { /* NOTE: currently this doesn't work, the below calculated samples_count seems to be right, but sometimes we just don't have all the data we need... */ if (ci->id3->frame_count) { /* TODO: 1152 is the frame size in samples for MPEG1 layer 2 and layer 3, it's probably not correct at all for MPEG2 and layer 1 */ samplecount = ((int64_t)ci->id3->frame_count) * 1152; } else { samplecount = ((int64_t)ci->id3->length) * current_frequency / 1000; } samplecount -= start_skip + stop_skip; } void init_mad(void) { ci->memset(&stream, 0, sizeof(struct mad_stream)); ci->memset(&frame, 0, sizeof(struct mad_frame)); ci->memset(&synth, 0, sizeof(struct mad_synth)); mad_stream_init(&stream); mad_frame_init(&frame); mad_synth_init(&synth); /* We do this so libmad doesn't try to call codec_calloc() */ ci->memset(mad_frame_overlap, 0, sizeof(mad_frame_overlap)); frame.overlap = &mad_frame_overlap; stream.main_data = &mad_main_data; } /* this is the codec entry point */ enum codec_status codec_start(struct codec_api *api) { int status = CODEC_OK; size_t size; int file_end; int frame_skip; /* samples to skip current frame */ int samples_to_skip; /* samples to skip in total for this file (at start) */ char *inputbuffer; ci = api; #ifdef USE_IRAM ci->memcpy(iramstart, iramcopy, iramend - iramstart); ci->memset(iedata, 0, iend - iedata); #endif if (codec_init(api)) return CODEC_ERROR; /* Create a decoder instance */ ci->configure(CODEC_DSP_ENABLE, (bool *)true); ci->configure(DSP_DITHER, (bool *)false); ci->configure(DSP_SET_SAMPLE_DEPTH, (int *)(MAD_F_FRACBITS)); ci->configure(DSP_SET_CLIP_MIN, (int *)-MAD_F_ONE); ci->configure(DSP_SET_CLIP_MAX, (int *)(MAD_F_ONE - 1)); ci->configure(CODEC_SET_FILEBUF_CHUNKSIZE, (int *)(1024*16)); /** This label might need to be moved above all the init code, but I don't * think reiniting the codec is necessary for MPEG. It might even be unwanted * for gapless playback. * Reinitializing seems to be necessary to avoid playback quircks when seeking. */ next_track: init_mad(); file_end = 0; while (!*ci->taginfo_ready && !ci->stop_codec) ci->sleep(1); ci->configure(DSP_SET_FREQUENCY, (int *)ci->id3->frequency); current_frequency = ci->id3->frequency; codec_set_replaygain(ci->id3); ci->request_buffer(&size, ci->id3->first_frame_offset); ci->advance_buffer(size); if (ci->id3->lead_trim >= 0 && ci->id3->tail_trim >= 0) { stop_skip = ci->id3->tail_trim - mpeg_latency[ci->id3->layer]; if (stop_skip < 0) stop_skip = 0; start_skip = ci->id3->lead_trim + mpeg_latency[ci->id3->layer]; } else { stop_skip = 0; /* We want to skip this amount anyway */ start_skip = mpeg_latency[ci->id3->layer]; } samplesdone = ((int64_t)ci->id3->elapsed) * current_frequency / 1000; samples_to_skip = start_skip; recalc_samplecount(); /* This is the decoding loop. */ while (1) { int framelength; ci->yield(); if (ci->stop_codec || ci->new_track) break; if (ci->seek_time) { int newpos; samplesdone = ((int64_t) (ci->seek_time - 1)) * current_frequency / 1000; if (ci->seek_time-1 == 0) newpos = 0; else newpos = ci->mp3_get_filepos(ci->seek_time-1) + ci->id3->first_frame_offset; if (!ci->seek_buffer(newpos)) goto next_track; ci->seek_complete(); init_mad(); } /* Lock buffers */ if (stream.error == 0) { inputbuffer = ci->request_buffer(&size, INPUT_CHUNK_SIZE); if (size == 0 || inputbuffer == NULL) break; mad_stream_buffer(&stream, (unsigned char *)inputbuffer, size); } if (mad_frame_decode(&frame, &stream)) { if (stream.error == MAD_FLAG_INCOMPLETE || stream.error == MAD_ERROR_BUFLEN) { /* This makes the codec support partially corrupted files */ if (file_end == 30) break; /* Fill the buffer */ if (stream.next_frame) ci->advance_buffer_loc((void *)stream.next_frame); else ci->advance_buffer(size); stream.error = 0; file_end++; continue; } else if (MAD_RECOVERABLE(stream.error)) { continue; } else { /* Some other unrecoverable error */ status = CODEC_ERROR; break; } break; } file_end = 0; mad_synth_frame(&synth, &frame); /* We need to skip samples_to_skip samples from the start of every file to properly support LAME style gapless MP3 files. samples_to_skip might be larger than one frame. */ if (samples_to_skip < synth.pcm.length) { /* skip just part of the frame */ frame_skip = samples_to_skip; samples_to_skip = 0; } else { /* we need to skip an entire frame */ frame_skip = synth.pcm.length; samples_to_skip -= synth.pcm.length; } framelength = synth.pcm.length - frame_skip; if (stop_skip > 0) { int64_t max = samplecount - samplesdone; if (max < 0) max = 0; if (max < framelength) framelength = (int)max; if (framelength == 0 && frame_skip == 0) break; } /* Check if sample rate and stereo settings changed in this frame. */ if (frame.header.samplerate != current_frequency) { current_frequency = frame.header.samplerate; ci->configure(DSP_SWITCH_FREQUENCY, (int *)current_frequency); recalc_samplecount(); } if (MAD_NCHANNELS(&frame.header) == 2) { if (current_stereo_mode != STEREO_NONINTERLEAVED) { ci->configure(DSP_SET_STEREO_MODE, (int *)STEREO_NONINTERLEAVED); current_stereo_mode = STEREO_NONINTERLEAVED; } } else { if (current_stereo_mode != STEREO_MONO) { ci->configure(DSP_SET_STEREO_MODE, (int *)STEREO_MONO); current_stereo_mode = STEREO_MONO; } } /* Check if we can just skip the entire frame. */ if (frame_skip < synth.pcm.length) { /* In case of a mono file, the second array will be ignored. */ ci->pcmbuf_insert_split(&synth.pcm.samples[0][frame_skip], &synth.pcm.samples[1][frame_skip], framelength * 4); } if (stream.next_frame) ci->advance_buffer_loc((void *)stream.next_frame); else ci->advance_buffer(size); samplesdone += framelength; ci->set_elapsed(samplesdone / (current_frequency / 1000)); } stream.error = 0; if (ci->request_next_track()) goto next_track; return status; }