/* 2004.02.01 first released source code for IOMP */ /* * Copyright (C) 2000-2001 the xine project * * This file is part of xine, a free video player. * * xine 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. * * xine 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 * * fooaudio.c: This is a reference audio decoder for the xine multimedia * player. It really works too! It will output a continuous sine wave in * place of the data it should actually send. * * $Id: fooaudio.c,v 1.2 2003/11/25 04:26:03 georgedon Exp $ */ #include #include #include #include #include #include "xine_internal.h" #include "audio_out.h" #include "buffer.h" #include "xineutils.h" #include "bswap.h" /* math.h required for fooaudio sine wave generation */ #include #define AUDIOBUFSIZE 128*1024 typedef struct { audio_decoder_class_t decoder_class; } fooaudio_class_t; typedef struct fooaudio_decoder_s { audio_decoder_t audio_decoder; xine_stream_t *stream; int sample_rate; /* audio sample rate */ int bits_per_sample; /* bits/sample, usually 8 or 16 */ int channels; /* 1 or 2, usually */ int output_open; /* flag to indicate audio is ready */ unsigned char *buf; /* data accumulation buffer */ int bufsize; /* maximum size of buf */ int size; /* size of accumulated data in buf */ /* fooaudio-specific variables */ int64_t last_pts; unsigned int iteration; } fooaudio_decoder_t; /************************************************************************** * fooaudio specific decode functions *************************************************************************/ /************************************************************************** * xine audio plugin functions *************************************************************************/ static void fooaudio_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) { fooaudio_decoder_t *this = (fooaudio_decoder_t *) this_gen; audio_buffer_t *audio_buffer; int i; int64_t samples_to_generate; int samples_to_send; if (buf->decoder_flags & BUF_FLAG_HEADER) { /* When the engine sends a BUF_FLAG_HEADER flag, it is time to initialize * the decoder. The buffer element type has 4 decoder_info fields, * 0..3. Field 1 is the sample rate. Field 2 is the bits/sample. Field * 3 is the number of channels. */ this->sample_rate = buf->decoder_info[1]; this->bits_per_sample = buf->decoder_info[2]; this->channels = buf->decoder_info[3]; /* initialize the data accumulation buffer */ this->buf = xine_xmalloc(AUDIOBUFSIZE); this->bufsize = AUDIOBUFSIZE; this->size = 0; /* take this opportunity to initialize stream/meta information */ this->stream->meta_info[XINE_META_INFO_AUDIOCODEC] = strdup("fooaudio"); /* peform any other required initialization */ this->last_pts = -1; this->iteration = 0; return; } /* if the audio output is not open yet, open the audio output */ #warning: Audio output is hardcoded to mono 16-bit PCM if (!this->output_open) { this->output_open = this->stream->audio_out->open( this->stream->audio_out, this->stream, /* this->bits_per_sample, */ 16, this->sample_rate, /* (this->channels == 2) ? AO_CAP_MODE_STEREO : AO_CAP_MODE_MONO);*/ AO_CAP_MODE_MONO); } /* if the audio still isn't open, do not go any further with the decode */ if (!this->output_open) return; /* accumulate the data passed through the buffer element type; increase * the accumulator buffer size as necessary */ if( this->size + buf->size > this->bufsize ) { this->bufsize = this->size + 2 * buf->size; printf("fooaudio: increasing source buffer to %d to avoid overflow.\n", this->bufsize); this->buf = realloc( this->buf, this->bufsize ); } xine_fast_memcpy (&this->buf[this->size], buf->content, buf->size); this->size += buf->size; /* When a buffer element type has the BUF_FLAG_FRAME_END flag set, it is * time to decode the data in the buffer. */ if (buf->decoder_flags & BUF_FLAG_FRAME_END) { /* This is where the real meat of the audio decoder is implemented. * The general strategy is to decode the data in the accumulation buffer * into raw PCM data and then dispatch the PCM to the engine in smaller * buffers. What follows in the inside of this scope is the meat of * this particular audio decoder. */ /* Operation of the fooaudio decoder: * This decoder generates a continuous sine pattern based on the pts * values sent by the xine engine. Two pts values are needed to know * how long to make the audio. Thus, If this is the first frame or * a seek has occurred (indicated by this->last_pts = -1), * log the pts but do not create any audio. * * When a valid pts delta is generated, create n audio samples, where * n is given as: * * n pts delta * ----------- = --------- => n = (pts delta * sample rate) / 90000 * sample rate 90000 * */ if (this->last_pts != -1) { /* no real reason to set this variable to 0 first; I just wanted the * novelty of using all 4 basic arithmetic ops in a row (+ - * /) */ samples_to_generate = 0; samples_to_generate += buf->pts; samples_to_generate -= this->last_pts; samples_to_generate *= this->sample_rate; samples_to_generate /= 90000; /* save the pts now since it will likely be trashed later */ this->last_pts = buf->pts; while (samples_to_generate) { /* get an audio buffer */ audio_buffer = this->stream->audio_out->get_buffer (this->stream->audio_out); if (audio_buffer->mem_size == 0) { printf ("fooaudio: Help! Allocated audio buffer with nothing in it!\n"); return; } /* samples_to_generate is a sample count; mem_size is a byte count */ if (samples_to_generate > audio_buffer->mem_size / 2) samples_to_send = audio_buffer->mem_size / 2; else samples_to_send = samples_to_generate; samples_to_generate -= samples_to_send; #define WAVE_HZ 300 /* fill up the samples in the buffer */ for (i = 0; i < samples_to_send; i++) audio_buffer->mem[i] = (short)(sin(2 * M_PI * this->iteration++ / WAVE_HZ) * 32767); /* final prep for audio buffer dispatch */ audio_buffer->num_frames = samples_to_send; audio_buffer->vpts = buf->pts; buf->pts = 0; /* only first buffer gets the real pts */ this->stream->audio_out->put_buffer (this->stream->audio_out, audio_buffer, this->stream); } } else { /* log the pts for the next time */ this->last_pts = buf->pts; } /* reset data accumulation buffer */ this->size = 0; } } /* This function resets the state of the audio decoder. This usually * entails resetting the data accumulation buffer. */ static void fooaudio_reset (audio_decoder_t *this_gen) { fooaudio_decoder_t *this = (fooaudio_decoder_t *) this_gen; this->size = 0; /* this is specific to fooaudio */ this->last_pts = -1; } /* This function resets the last pts value of the audio decoder. */ static void fooaudio_discontinuity (audio_decoder_t *this_gen) { fooaudio_decoder_t *this = (fooaudio_decoder_t *) this_gen; /* this is specific to fooaudio */ this->last_pts = -1; } /* This function closes the audio output and frees the private audio decoder * structure. */ static void fooaudio_dispose (audio_decoder_t *this_gen) { fooaudio_decoder_t *this = (fooaudio_decoder_t *) this_gen; /* close the audio output */ if (this->output_open) this->stream->audio_out->close (this->stream->audio_out, this->stream); this->output_open = 0; /* free anything that was allocated during operation */ free(this->buf); free(this); } /* This function allocates, initializes, and returns a private audio * decoder structure. */ static audio_decoder_t *open_plugin (audio_decoder_class_t *class_gen, xine_stream_t *stream) { fooaudio_decoder_t *this ; this = (fooaudio_decoder_t *) malloc (sizeof (fooaudio_decoder_t)); /* connect the member functions */ this->audio_decoder.decode_data = fooaudio_decode_data; this->audio_decoder.reset = fooaudio_reset; this->audio_decoder.discontinuity = fooaudio_discontinuity; this->audio_decoder.dispose = fooaudio_dispose; /* connect the stream */ this->stream = stream; /* audio output is not open at the start */ this->output_open = 0; /* initialize the basic audio parameters */ this->channels = 0; this->sample_rate = 0; this->bits_per_sample = 0; /* initialize the data accumulation buffer */ this->buf = NULL; this->bufsize = 0; this->size = 0; /* return the newly-initialized audio decoder */ return &this->audio_decoder; } /* This function returns a brief string that describes (usually with the * decoder's most basic name) the audio decoder plugin. */ static char *get_identifier (audio_decoder_class_t *this) { return "fooaudio"; } /* This function returns a slightly longer string describing the audio * decoder plugin. */ static char *get_description (audio_decoder_class_t *this) { return "fooaudio: reference xine audio decoder plugin"; } /* This function frees the audio decoder class and any other memory that was * allocated. */ static void dispose_class (audio_decoder_class_t *this_gen) { fooaudio_class_t *this = (fooaudio_class_t *)this_gen; free (this); } /* This function allocates a private audio decoder class and initializes * the class's member functions. */ static void *init_plugin (xine_t *xine, void *data) { fooaudio_class_t *this ; this = (fooaudio_class_t *) malloc (sizeof (fooaudio_class_t)); this->decoder_class.open_plugin = open_plugin; this->decoder_class.get_identifier = get_identifier; this->decoder_class.get_description = get_description; this->decoder_class.dispose = dispose_class; return this; } /* This is a list of all of the internal xine audio buffer types that * this decoder is able to handle. Check src/xine-engine/buffer.h for a * list of valid buffer types (and add a new one if the one you need does * not exist). Terminate the list with a 0. */ static uint32_t audio_types[] = { /* BUF_AUDIO_FOO, */ 0 }; /* This data structure combines the list of supported xine buffer types and * the priority that the plugin should be given with respect to other * plugins that handle the same buffer type. A plugin with priority (n+1) * will be used instead of a plugin with priority (n). */ static decoder_info_t dec_info_audio = { audio_types, /* supported types */ 5 /* priority */ }; /* The plugin catalog entry. This is the only information that this plugin * will export to the public. */ plugin_info_t xine_plugin_info[] = { /* { type, API version, "name", version, special_info, init_function }, */ { PLUGIN_AUDIO_DECODER, 13, "fooaudio", XINE_VERSION_CODE, &dec_info_audio, &init_plugin }, { PLUGIN_NONE, 0, "", 0, NULL, NULL } };