X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftags%2Fsynfig_0_61_05%2Fsynfig-core%2Fsrc%2Fmodules%2Fmod_libavcodec%2Flibavcodec%2Fa52dec.c;fp=synfig-core%2Ftags%2Fsynfig_0_61_05%2Fsynfig-core%2Fsrc%2Fmodules%2Fmod_libavcodec%2Flibavcodec%2Fa52dec.c;h=fb169c7ee38d4177ec8d168a9f38c23f9480d0da;hb=299aecad571ca490ce017004a0d7e555d6df0520;hp=0000000000000000000000000000000000000000;hpb=42861dc634bef4059ca95e5292033315a0b9ce30;p=synfig.git diff --git a/synfig-core/tags/synfig_0_61_05/synfig-core/src/modules/mod_libavcodec/libavcodec/a52dec.c b/synfig-core/tags/synfig_0_61_05/synfig-core/src/modules/mod_libavcodec/libavcodec/a52dec.c new file mode 100644 index 0000000..fb169c7 --- /dev/null +++ b/synfig-core/tags/synfig_0_61_05/synfig-core/src/modules/mod_libavcodec/libavcodec/a52dec.c @@ -0,0 +1,256 @@ +/* + * A52 decoder + * Copyright (c) 2001 Fabrice Bellard. + * + * 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 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 + */ + +/** + * @file a52dec.c + * A52 decoder. + */ + +#include "avcodec.h" +#include "liba52/a52.h" + +#ifdef CONFIG_A52BIN +#include +static const char* liba52name = "liba52.so.0"; +#endif + +/** + * liba52 - Copyright (C) Aaron Holtzman + * released under the GPL license. + */ +typedef struct AC3DecodeState { + uint8_t inbuf[4096]; /* input buffer */ + uint8_t *inbuf_ptr; + int frame_size; + int flags; + int channels; + a52_state_t* state; + sample_t* samples; + + /* + * virtual method table + * + * using this function table so the liba52 doesn't + * have to be really linked together with ffmpeg + * and might be linked in runtime - this allows binary + * distribution of ffmpeg library which doens't depend + * on liba52 library - but if user has it installed + * it will be used - user might install such library + * separately + */ + void* handle; + a52_state_t* (*a52_init)(uint32_t mm_accel); + sample_t* (*a52_samples)(a52_state_t * state); + int (*a52_syncinfo)(uint8_t * buf, int * flags, + int * sample_rate, int * bit_rate); + int (*a52_frame)(a52_state_t * state, uint8_t * buf, int * flags, + sample_t * level, sample_t bias); + void (*a52_dynrng)(a52_state_t * state, + sample_t (* call) (sample_t, void *), void * data); + int (*a52_block)(a52_state_t * state); + void (*a52_free)(a52_state_t * state); + +} AC3DecodeState; + +#ifdef CONFIG_A52BIN +static void* dlsymm(void* handle, const char* symbol) +{ + void* f = dlsym(handle, symbol); + if (!f) + fprintf(stderr, "A52 Decoder - function '%s' can't be resolved\n", symbol); + return f; +} +#endif + +static int a52_decode_init(AVCodecContext *avctx) +{ + AC3DecodeState *s = avctx->priv_data; + +#ifdef CONFIG_A52BIN + s->handle = dlopen(liba52name, RTLD_LAZY); + if (!s->handle) + { + fprintf(stderr, "A52 library %s could not be opened! \n%s\n", liba52name, dlerror()); + return -1; + } + s->a52_init = (a52_state_t* (*)(uint32_t)) dlsymm(s->handle, "a52_init"); + s->a52_samples = (sample_t* (*)(a52_state_t*)) dlsymm(s->handle, "a52_samples"); + s->a52_syncinfo = (int (*)(uint8_t*, int*, int*, int*)) dlsymm(s->handle, "a52_syncinfo"); + s->a52_frame = (int (*)(a52_state_t*, uint8_t*, int*, sample_t*, sample_t)) dlsymm(s->handle, "a52_frame"); + s->a52_block = (int (*)(a52_state_t*)) dlsymm(s->handle, "a52_block"); + s->a52_free = (void (*)(a52_state_t*)) dlsymm(s->handle, "a52_free"); + if (!s->a52_init || !s->a52_samples || !s->a52_syncinfo + || !s->a52_frame || !s->a52_block || !s->a52_free) + { + dlclose(s->handle); + return -1; + } +#else + /* static linked version */ + s->handle = 0; + s->a52_init = a52_init; + s->a52_samples = a52_samples; + s->a52_syncinfo = a52_syncinfo; + s->a52_frame = a52_frame; + s->a52_block = a52_block; + s->a52_free = a52_free; +#endif + s->state = s->a52_init(0); /* later use CPU flags */ + s->samples = s->a52_samples(s->state); + s->inbuf_ptr = s->inbuf; + s->frame_size = 0; + + return 0; +} + +/**** the following two functions comes from a52dec */ +static inline int blah (int32_t i) +{ + if (i > 0x43c07fff) + return 32767; + else if (i < 0x43bf8000) + return -32768; + return i - 0x43c00000; +} + +static inline void float_to_int (float * _f, int16_t * s16, int nchannels) +{ + int i, j, c; + int32_t * f = (int32_t *) _f; // XXX assumes IEEE float format + + j = 0; + nchannels *= 256; + for (i = 0; i < 256; i++) { + for (c = 0; c < nchannels; c += 256) + s16[j++] = blah (f[i + c]); + } +} + +/**** end */ + +#define HEADER_SIZE 7 + +static int a52_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + uint8_t *buf, int buf_size) +{ + AC3DecodeState *s = avctx->priv_data; + uint8_t *buf_ptr; + int flags, i, len; + int sample_rate, bit_rate; + short *out_samples = data; + float level; + static const int ac3_channels[8] = { + 2, 1, 2, 3, 3, 4, 4, 5 + }; + + *data_size = 0; + buf_ptr = buf; + while (buf_size > 0) { + len = s->inbuf_ptr - s->inbuf; + if (s->frame_size == 0) { + /* no header seen : find one. We need at least 7 bytes to parse it */ + len = HEADER_SIZE - len; + if (len > buf_size) + len = buf_size; + memcpy(s->inbuf_ptr, buf_ptr, len); + buf_ptr += len; + s->inbuf_ptr += len; + buf_size -= len; + if ((s->inbuf_ptr - s->inbuf) == HEADER_SIZE) { + len = s->a52_syncinfo(s->inbuf, &s->flags, &sample_rate, &bit_rate); + if (len == 0) { + /* no sync found : move by one byte (inefficient, but simple!) */ + memcpy(s->inbuf, s->inbuf + 1, HEADER_SIZE - 1); + s->inbuf_ptr--; + } else { + s->frame_size = len; + /* update codec info */ + avctx->sample_rate = sample_rate; + s->channels = ac3_channels[s->flags & 7]; + if (s->flags & A52_LFE) + s->channels++; + if (avctx->channels == 0) + /* No specific number of channel requested */ + avctx->channels = s->channels; + else if (s->channels < avctx->channels) { + fprintf(stderr, "ac3dec: AC3 Source channels are less than specified: output to %d channels.. (frmsize: %d)\n", s->channels, len); + avctx->channels = s->channels; + } + avctx->bit_rate = bit_rate; + } + } + } else if (len < s->frame_size) { + len = s->frame_size - len; + if (len > buf_size) + len = buf_size; + + memcpy(s->inbuf_ptr, buf_ptr, len); + buf_ptr += len; + s->inbuf_ptr += len; + buf_size -= len; + } else { + flags = s->flags; + if (avctx->channels == 1) + flags = A52_MONO; + else if (avctx->channels == 2) + flags = A52_STEREO; + else + flags |= A52_ADJUST_LEVEL; + level = 1; + if (s->a52_frame(s->state, s->inbuf, &flags, &level, 384)) { + fail: + s->inbuf_ptr = s->inbuf; + s->frame_size = 0; + continue; + } + for (i = 0; i < 6; i++) { + if (s->a52_block(s->state)) + goto fail; + float_to_int(s->samples, out_samples + i * 256 * avctx->channels, avctx->channels); + } + s->inbuf_ptr = s->inbuf; + s->frame_size = 0; + *data_size = 6 * avctx->channels * 256 * sizeof(int16_t); + break; + } + } + return buf_ptr - buf; +} + +static int a52_decode_end(AVCodecContext *avctx) +{ + AC3DecodeState *s = avctx->priv_data; + s->a52_free(s->state); +#ifdef CONFIG_A52BIN + dlclose(s->handle); +#endif + return 0; +} + +AVCodec ac3_decoder = { + "ac3", + CODEC_TYPE_AUDIO, + CODEC_ID_AC3, + sizeof(AC3DecodeState), + a52_decode_init, + NULL, + a52_decode_end, + a52_decode_frame, +};