# HG changeset patch # User Ryan C. Gordon # Date 1014320539 0 # Node ID b6c47452f4aacf43aa89232f4f0b10fbe73184a3 # Parent 8fa2a9b2642effd6905123fb6b7e71cd9219ec1c Renamed to smpeg.c ... diff -r 8fa2a9b2642e -r b6c47452f4aa decoders/mp3.c --- a/decoders/mp3.c Tue Feb 12 03:07:37 2002 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,280 +0,0 @@ -/* - * SDL_sound -- An abstract sound format decoding API. - * Copyright (C) 2001 Ryan C. Gordon. - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * This library 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -/* - * MPEG-1 Layer 3, or simply, "MP3", decoder for SDL_sound. - * - * This driver handles all those highly compressed songs you stole through - * Napster. :) It depends on the SMPEG library for decoding, which can - * be grabbed from: http://www.lokigames.com/development/smpeg.php3 - * - * This should also be able to extract the audio stream from an MPEG movie. - * - * Please see the file COPYING in the source's root directory. - * - * This file written by Ryan C. Gordon. (icculus@clutteredmind.org) - */ - -#if HAVE_CONFIG_H -# include -#endif - -#ifdef SOUND_SUPPORTS_MP3 - -#include -#include -#include -#include - -#include "SDL_sound.h" - -#define __SDL_SOUND_INTERNAL__ -#include "SDL_sound_internal.h" - -#include "smpeg.h" -#include "extra_rwops.h" - - -static int MP3_init(void); -static void MP3_quit(void); -static int MP3_open(Sound_Sample *sample, const char *ext); -static void MP3_close(Sound_Sample *sample); -static Uint32 MP3_read(Sound_Sample *sample); -static int MP3_rewind(Sound_Sample *sample); - -static const char *extensions_smpeg[] = { "MP3", "MPEG", "MPG", NULL }; -const Sound_DecoderFunctions __Sound_DecoderFunctions_MP3 = -{ - { - extensions_smpeg, - "MPEG-1 Layer 3 audio through SMPEG", - "Ryan C. Gordon ", - "http://www.lokigames.com/development/smpeg.php3" - }, - - MP3_init, /* init() method */ - MP3_quit, /* quit() method */ - MP3_open, /* open() method */ - MP3_close, /* close() method */ - MP3_read, /* read() method */ - MP3_rewind /* rewind() method */ -}; - - -static int MP3_init(void) -{ - return(1); /* always succeeds. */ -} /* MP3_init */ - - -static void MP3_quit(void) -{ - /* it's a no-op. */ -} /* MP3_quit */ - - -static __inline__ void output_version(void) -{ - static int first_time = 1; - - if (first_time) - { - SMPEG_version v; - SMPEG_VERSION(&v); - SNDDBG(("MP3: Compiled against SMPEG v%d.%d.%d.\n", - v.major, v.minor, v.patch)); - first_time = 0; - } /* if */ -} /* output_version */ - - -static int MP3_open(Sound_Sample *sample, const char *ext) -{ - SMPEG *smpeg; - SMPEG_Info smpeg_info; - SDL_AudioSpec spec; - Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; - SDL_RWops *refCounter; - - output_version(); - - /* - * If I understand things correctly, MP3 files don't really have any - * magic header we can check for. The MP3 player is expected to just - * pick the first thing that looks like a valid frame and start - * playing from there. - * - * So here's what we do: If the caller insists that this is really - * MP3 we'll take his word for it. Otherwise, use the same test as - * SDL_mixer does and check if the stream starts with something that - * looks like a frame. - * - * A frame begins with 11 bits of frame sync (all bits must be set), - * followed by a two-bit MPEG Audio version ID: - * - * 00 - MPEG Version 2.5 (later extension of MPEG 2) - * 01 - reserved - * 10 - MPEG Version 2 (ISO/IEC 13818-3) - * 11 - MPEG Version 1 (ISO/IEC 11172-3) - * - * Apparently we don't handle MPEG Version 2.5. - */ - if (__Sound_strcasecmp(ext, "MP3") != 0) - { - Uint8 mp3_magic[2]; - - if (SDL_RWread(internal->rw, mp3_magic, sizeof (mp3_magic), 1) != 1) - { - Sound_SetError("MP3: Could not read MP3 magic."); - return(0); - } /*if */ - - if (mp3_magic[0] != 0xFF || (mp3_magic[1] & 0xF0) != 0xF0) - { - Sound_SetError("MP3: Not an MP3 stream."); - return(0); - } /* if */ - - /* !!! FIXME: If the seek fails, we'll probably miss a frame */ - SDL_RWseek(internal->rw, -sizeof (mp3_magic), SEEK_CUR); - } /* if */ - - refCounter = RWops_RWRefCounter_new(internal->rw); - if (refCounter == NULL) - { - SNDDBG(("MP3: Failed to create reference counting RWops.\n")); - return(0); - } /* if */ - - /* replace original RWops. This is safe. Honest. :) */ - internal->rw = refCounter; - - /* - * increment the refcount, since SMPEG will nuke the RWops if it can't - * accept the contained data... - */ - RWops_RWRefCounter_addRef(refCounter); - smpeg = SMPEG_new_rwops(refCounter, &smpeg_info, 0); - - if (SMPEG_error(smpeg)) - { - Sound_SetError(SMPEG_error(smpeg)); - SMPEG_delete(smpeg); - return(0); - } /* if */ - - if (!smpeg_info.has_audio) - { - Sound_SetError("MP3: No audio stream found in data."); - SMPEG_delete(smpeg); - return(0); - } /* if */ - - SNDDBG(("MP3: Accepting data stream.\n")); - SNDDBG(("MP3: has_audio == {%s}.\n", smpeg_info.has_audio ? "TRUE" : "FALSE")); - SNDDBG(("MP3: has_video == {%s}.\n", smpeg_info.has_video ? "TRUE" : "FALSE")); - SNDDBG(("MP3: width == (%d).\n", smpeg_info.width)); - SNDDBG(("MP3: height == (%d).\n", smpeg_info.height)); - SNDDBG(("MP3: current_frame == (%d).\n", smpeg_info.current_frame)); - SNDDBG(("MP3: current_fps == (%f).\n", smpeg_info.current_fps)); - SNDDBG(("MP3: audio_string == [%s].\n", smpeg_info.audio_string)); - SNDDBG(("MP3: audio_current_frame == (%d).\n", smpeg_info.audio_current_frame)); - SNDDBG(("MP3: current_offset == (%d).\n", smpeg_info.current_offset)); - SNDDBG(("MP3: total_size == (%d).\n", smpeg_info.total_size)); - SNDDBG(("MP3: current_time == (%f).\n", smpeg_info.current_time)); - SNDDBG(("MP3: total_time == (%f).\n", smpeg_info.total_time)); - - SMPEG_enablevideo(smpeg, 0); - SMPEG_enableaudio(smpeg, 1); - SMPEG_loop(smpeg, 0); - - SMPEG_wantedSpec(smpeg, &spec); - - /* - * One of the MP3s I tried wouldn't work unless I added this line - * to tell SMPEG that yes, it may have the spec it wants. - */ - SMPEG_actualSpec(smpeg, &spec); - sample->actual.format = spec.format; - sample->actual.rate = spec.freq; - sample->actual.channels = spec.channels; - sample->flags = SOUND_SAMPLEFLAG_NONE; - internal->decoder_private = smpeg; - - SMPEG_play(smpeg); - return(1); -} /* MP3_open */ - - -static void MP3_close(Sound_Sample *sample) -{ - Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; - SMPEG_delete((SMPEG *) internal->decoder_private); -} /* MP3_close */ - - -static Uint32 MP3_read(Sound_Sample *sample) -{ - Uint32 retval; - Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; - SMPEG *smpeg = (SMPEG *) internal->decoder_private; - - /* - * We have to clear the buffer because apparently SMPEG_playAudio() - * will mix the decoded audio with whatever's already in it. Nasty. - */ - memset(internal->buffer, '\0', internal->buffer_size); - retval = SMPEG_playAudio(smpeg, internal->buffer, internal->buffer_size); - if (retval < internal->buffer_size) - { - char *errMsg = SMPEG_error(smpeg); - if (errMsg == NULL) - sample->flags |= SOUND_SAMPLEFLAG_EOF; - else - { - Sound_SetError(errMsg); - sample->flags |= SOUND_SAMPLEFLAG_ERROR; - } /* else */ - } /* if */ - - return(retval); -} /* MP3_read */ - - -static int MP3_rewind(Sound_Sample *sample) -{ - Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; - SMPEG *smpeg = (SMPEG *) internal->decoder_private; - SMPEGstatus status; - - /* - * SMPEG_rewind() really means "stop and rewind", so we may have to - * restart it afterwards. - */ - status = SMPEG_status(smpeg); - SMPEG_rewind(smpeg); - if (status == SMPEG_PLAYING) - SMPEG_play(smpeg); - return(1); -} /* MP3_rewind */ - -#endif /* SOUND_SUPPORTS_MP3 */ - -/* end of mp3.c ... */ -