/* * LucasArts VIMA decoder * Copyright (c) 2012 Paul B Mahol * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/channel_layout.h" #include "avcodec.h" #include "get_bits.h" #include "adpcm_data.h" typedef struct { AVFrame frame; uint16_t predict_table[5786 * 2]; } VimaContext; static const uint8_t size_table[] = { 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 }; static const int8_t index_table1[] = { -1, 4, -1, 4 }; static const int8_t index_table2[] = { -1, -1, 2, 6, -1, -1, 2, 6 }; static const int8_t index_table3[] = { -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6 }; static const int8_t index_table4[] = { -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6 }; static const int8_t index_table5[] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6 }; static const int8_t index_table6[] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6 }; static const int8_t* const step_index_tables[] = { index_table1, index_table2, index_table3, index_table4, index_table5, index_table6 }; static av_cold int decode_init(AVCodecContext *avctx) { VimaContext *vima = avctx->priv_data; int start_pos; for (start_pos = 0; start_pos < 64; start_pos++) { unsigned int dest_pos, table_pos; for (table_pos = 0, dest_pos = start_pos; table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table); table_pos++, dest_pos += 64) { int put = 0, count, table_value; table_value = ff_adpcm_step_table[table_pos]; for (count = 32; count != 0; count >>= 1) { if (start_pos & count) put += table_value; table_value >>= 1; } vima->predict_table[dest_pos] = put; } } avcodec_get_frame_defaults(&vima->frame); avctx->coded_frame = &vima->frame; avctx->sample_fmt = AV_SAMPLE_FMT_S16; return 0; } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *pkt) { GetBitContext gb; VimaContext *vima = avctx->priv_data; int16_t pcm_data[2]; uint32_t samples; int8_t channel_hint[2]; int ret, chan, channels = 1; if (pkt->size < 13) return AVERROR_INVALIDDATA; init_get_bits(&gb, pkt->data, pkt->size * 8); samples = get_bits_long(&gb, 32); if (samples == 0xffffffff) { skip_bits_long(&gb, 32); samples = get_bits_long(&gb, 32); } if (samples > pkt->size * 2) return AVERROR_INVALIDDATA; channel_hint[0] = get_sbits(&gb, 8); if (channel_hint[0] & 0x80) { channel_hint[0] = ~channel_hint[0]; channels = 2; } avctx->channels = channels; avctx->channel_layout = (channels == 2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO; pcm_data[0] = get_sbits(&gb, 16); if (channels > 1) { channel_hint[1] = get_sbits(&gb, 8); pcm_data[1] = get_sbits(&gb, 16); } vima->frame.nb_samples = samples; if ((ret = avctx->get_buffer(avctx, &vima->frame)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } for (chan = 0; chan < channels; chan++) { uint16_t *dest = (uint16_t*)vima->frame.data[0] + chan; int step_index = channel_hint[chan]; int output = pcm_data[chan]; int sample; for (sample = 0; sample < samples; sample++) { int lookup_size, lookup, highbit, lowbits; step_index = av_clip(step_index, 0, 88); lookup_size = size_table[step_index]; lookup = get_bits(&gb, lookup_size); highbit = 1 << (lookup_size - 1); lowbits = highbit - 1; if (lookup & highbit) lookup ^= highbit; else highbit = 0; if (lookup == lowbits) { output = get_sbits(&gb, 16); } else { int predict_index, diff; predict_index = (lookup << (7 - lookup_size)) | (step_index << 6); predict_index = av_clip(predict_index, 0, 5785); diff = vima->predict_table[predict_index]; if (lookup) diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1); if (highbit) diff = -diff; output = av_clip_int16(output + diff); } *dest = output; dest += channels; step_index += step_index_tables[lookup_size - 2][lookup]; } } *got_frame_ptr = 1; *(AVFrame *)data = vima->frame; return pkt->size; } AVCodec ff_vima_decoder = { .name = "vima", .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_VIMA, .priv_data_size = sizeof(VimaContext), .init = decode_init, .decode = decode_frame, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"), };