yading@10: /* yading@10: * ALAC audio encoder yading@10: * Copyright (c) 2008 Jaikrishnan Menon yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: #include "avcodec.h" yading@10: #include "put_bits.h" yading@10: #include "internal.h" yading@10: #include "lpc.h" yading@10: #include "mathops.h" yading@10: #include "alac_data.h" yading@10: yading@10: #define DEFAULT_FRAME_SIZE 4096 yading@10: #define ALAC_EXTRADATA_SIZE 36 yading@10: #define ALAC_FRAME_HEADER_SIZE 55 yading@10: #define ALAC_FRAME_FOOTER_SIZE 3 yading@10: yading@10: #define ALAC_ESCAPE_CODE 0x1FF yading@10: #define ALAC_MAX_LPC_ORDER 30 yading@10: #define DEFAULT_MAX_PRED_ORDER 6 yading@10: #define DEFAULT_MIN_PRED_ORDER 4 yading@10: #define ALAC_MAX_LPC_PRECISION 9 yading@10: #define ALAC_MAX_LPC_SHIFT 9 yading@10: yading@10: #define ALAC_CHMODE_LEFT_RIGHT 0 yading@10: #define ALAC_CHMODE_LEFT_SIDE 1 yading@10: #define ALAC_CHMODE_RIGHT_SIDE 2 yading@10: #define ALAC_CHMODE_MID_SIDE 3 yading@10: yading@10: typedef struct RiceContext { yading@10: int history_mult; yading@10: int initial_history; yading@10: int k_modifier; yading@10: int rice_modifier; yading@10: } RiceContext; yading@10: yading@10: typedef struct AlacLPCContext { yading@10: int lpc_order; yading@10: int lpc_coeff[ALAC_MAX_LPC_ORDER+1]; yading@10: int lpc_quant; yading@10: } AlacLPCContext; yading@10: yading@10: typedef struct AlacEncodeContext { yading@10: int frame_size; /**< current frame size */ yading@10: int verbatim; /**< current frame verbatim mode flag */ yading@10: int compression_level; yading@10: int min_prediction_order; yading@10: int max_prediction_order; yading@10: int max_coded_frame_size; yading@10: int write_sample_size; yading@10: int extra_bits; yading@10: int32_t sample_buf[2][DEFAULT_FRAME_SIZE]; yading@10: int32_t predictor_buf[DEFAULT_FRAME_SIZE]; yading@10: int interlacing_shift; yading@10: int interlacing_leftweight; yading@10: PutBitContext pbctx; yading@10: RiceContext rc; yading@10: AlacLPCContext lpc[2]; yading@10: LPCContext lpc_ctx; yading@10: AVCodecContext *avctx; yading@10: } AlacEncodeContext; yading@10: yading@10: yading@10: static void init_sample_buffers(AlacEncodeContext *s, int channels, yading@10: uint8_t const *samples[2]) yading@10: { yading@10: int ch, i; yading@10: int shift = av_get_bytes_per_sample(s->avctx->sample_fmt) * 8 - yading@10: s->avctx->bits_per_raw_sample; yading@10: yading@10: #define COPY_SAMPLES(type) do { \ yading@10: for (ch = 0; ch < channels; ch++) { \ yading@10: int32_t *bptr = s->sample_buf[ch]; \ yading@10: const type *sptr = (const type *)samples[ch]; \ yading@10: for (i = 0; i < s->frame_size; i++) \ yading@10: bptr[i] = sptr[i] >> shift; \ yading@10: } \ yading@10: } while (0) yading@10: yading@10: if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S32P) yading@10: COPY_SAMPLES(int32_t); yading@10: else yading@10: COPY_SAMPLES(int16_t); yading@10: } yading@10: yading@10: static void encode_scalar(AlacEncodeContext *s, int x, yading@10: int k, int write_sample_size) yading@10: { yading@10: int divisor, q, r; yading@10: yading@10: k = FFMIN(k, s->rc.k_modifier); yading@10: divisor = (1< 8) { yading@10: // write escape code and sample value directly yading@10: put_bits(&s->pbctx, 9, ALAC_ESCAPE_CODE); yading@10: put_bits(&s->pbctx, write_sample_size, x); yading@10: } else { yading@10: if (q) yading@10: put_bits(&s->pbctx, q, (1<pbctx, 1, 0); yading@10: yading@10: if (k != 1) { yading@10: if (r > 0) yading@10: put_bits(&s->pbctx, k, r+1); yading@10: else yading@10: put_bits(&s->pbctx, k-1, 0); yading@10: } yading@10: } yading@10: } yading@10: yading@10: static void write_element_header(AlacEncodeContext *s, yading@10: enum AlacRawDataBlockType element, yading@10: int instance) yading@10: { yading@10: int encode_fs = 0; yading@10: yading@10: if (s->frame_size < DEFAULT_FRAME_SIZE) yading@10: encode_fs = 1; yading@10: yading@10: put_bits(&s->pbctx, 3, element); // element type yading@10: put_bits(&s->pbctx, 4, instance); // element instance yading@10: put_bits(&s->pbctx, 12, 0); // unused header bits yading@10: put_bits(&s->pbctx, 1, encode_fs); // Sample count is in the header yading@10: put_bits(&s->pbctx, 2, s->extra_bits >> 3); // Extra bytes (for 24-bit) yading@10: put_bits(&s->pbctx, 1, s->verbatim); // Audio block is verbatim yading@10: if (encode_fs) yading@10: put_bits32(&s->pbctx, s->frame_size); // No. of samples in the frame yading@10: } yading@10: yading@10: static void calc_predictor_params(AlacEncodeContext *s, int ch) yading@10: { yading@10: int32_t coefs[MAX_LPC_ORDER][MAX_LPC_ORDER]; yading@10: int shift[MAX_LPC_ORDER]; yading@10: int opt_order; yading@10: yading@10: if (s->compression_level == 1) { yading@10: s->lpc[ch].lpc_order = 6; yading@10: s->lpc[ch].lpc_quant = 6; yading@10: s->lpc[ch].lpc_coeff[0] = 160; yading@10: s->lpc[ch].lpc_coeff[1] = -190; yading@10: s->lpc[ch].lpc_coeff[2] = 170; yading@10: s->lpc[ch].lpc_coeff[3] = -130; yading@10: s->lpc[ch].lpc_coeff[4] = 80; yading@10: s->lpc[ch].lpc_coeff[5] = -25; yading@10: } else { yading@10: opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, s->sample_buf[ch], yading@10: s->frame_size, yading@10: s->min_prediction_order, yading@10: s->max_prediction_order, yading@10: ALAC_MAX_LPC_PRECISION, coefs, shift, yading@10: FF_LPC_TYPE_LEVINSON, 0, yading@10: ORDER_METHOD_EST, ALAC_MAX_LPC_SHIFT, 1); yading@10: yading@10: s->lpc[ch].lpc_order = opt_order; yading@10: s->lpc[ch].lpc_quant = shift[opt_order-1]; yading@10: memcpy(s->lpc[ch].lpc_coeff, coefs[opt_order-1], opt_order*sizeof(int)); yading@10: } yading@10: } yading@10: yading@10: static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n) yading@10: { yading@10: int i, best; yading@10: int32_t lt, rt; yading@10: uint64_t sum[4]; yading@10: uint64_t score[4]; yading@10: yading@10: /* calculate sum of 2nd order residual for each channel */ yading@10: sum[0] = sum[1] = sum[2] = sum[3] = 0; yading@10: for (i = 2; i < n; i++) { yading@10: lt = left_ch[i] - 2 * left_ch[i - 1] + left_ch[i - 2]; yading@10: rt = right_ch[i] - 2 * right_ch[i - 1] + right_ch[i - 2]; yading@10: sum[2] += FFABS((lt + rt) >> 1); yading@10: sum[3] += FFABS(lt - rt); yading@10: sum[0] += FFABS(lt); yading@10: sum[1] += FFABS(rt); yading@10: } yading@10: yading@10: /* calculate score for each mode */ yading@10: score[0] = sum[0] + sum[1]; yading@10: score[1] = sum[0] + sum[3]; yading@10: score[2] = sum[1] + sum[3]; yading@10: score[3] = sum[2] + sum[3]; yading@10: yading@10: /* return mode with lowest score */ yading@10: best = 0; yading@10: for (i = 1; i < 4; i++) { yading@10: if (score[i] < score[best]) yading@10: best = i; yading@10: } yading@10: return best; yading@10: } yading@10: yading@10: static void alac_stereo_decorrelation(AlacEncodeContext *s) yading@10: { yading@10: int32_t *left = s->sample_buf[0], *right = s->sample_buf[1]; yading@10: int i, mode, n = s->frame_size; yading@10: int32_t tmp; yading@10: yading@10: mode = estimate_stereo_mode(left, right, n); yading@10: yading@10: switch (mode) { yading@10: case ALAC_CHMODE_LEFT_RIGHT: yading@10: s->interlacing_leftweight = 0; yading@10: s->interlacing_shift = 0; yading@10: break; yading@10: case ALAC_CHMODE_LEFT_SIDE: yading@10: for (i = 0; i < n; i++) yading@10: right[i] = left[i] - right[i]; yading@10: s->interlacing_leftweight = 1; yading@10: s->interlacing_shift = 0; yading@10: break; yading@10: case ALAC_CHMODE_RIGHT_SIDE: yading@10: for (i = 0; i < n; i++) { yading@10: tmp = right[i]; yading@10: right[i] = left[i] - right[i]; yading@10: left[i] = tmp + (right[i] >> 31); yading@10: } yading@10: s->interlacing_leftweight = 1; yading@10: s->interlacing_shift = 31; yading@10: break; yading@10: default: yading@10: for (i = 0; i < n; i++) { yading@10: tmp = left[i]; yading@10: left[i] = (tmp + right[i]) >> 1; yading@10: right[i] = tmp - right[i]; yading@10: } yading@10: s->interlacing_leftweight = 1; yading@10: s->interlacing_shift = 1; yading@10: break; yading@10: } yading@10: } yading@10: yading@10: static void alac_linear_predictor(AlacEncodeContext *s, int ch) yading@10: { yading@10: int i; yading@10: AlacLPCContext lpc = s->lpc[ch]; yading@10: yading@10: if (lpc.lpc_order == 31) { yading@10: s->predictor_buf[0] = s->sample_buf[ch][0]; yading@10: yading@10: for (i = 1; i < s->frame_size; i++) { yading@10: s->predictor_buf[i] = s->sample_buf[ch][i ] - yading@10: s->sample_buf[ch][i - 1]; yading@10: } yading@10: yading@10: return; yading@10: } yading@10: yading@10: // generalised linear predictor yading@10: yading@10: if (lpc.lpc_order > 0) { yading@10: int32_t *samples = s->sample_buf[ch]; yading@10: int32_t *residual = s->predictor_buf; yading@10: yading@10: // generate warm-up samples yading@10: residual[0] = samples[0]; yading@10: for (i = 1; i <= lpc.lpc_order; i++) yading@10: residual[i] = samples[i] - samples[i-1]; yading@10: yading@10: // perform lpc on remaining samples yading@10: for (i = lpc.lpc_order + 1; i < s->frame_size; i++) { yading@10: int sum = 1 << (lpc.lpc_quant - 1), res_val, j; yading@10: yading@10: for (j = 0; j < lpc.lpc_order; j++) { yading@10: sum += (samples[lpc.lpc_order-j] - samples[0]) * yading@10: lpc.lpc_coeff[j]; yading@10: } yading@10: yading@10: sum >>= lpc.lpc_quant; yading@10: sum += samples[0]; yading@10: residual[i] = sign_extend(samples[lpc.lpc_order+1] - sum, yading@10: s->write_sample_size); yading@10: res_val = residual[i]; yading@10: yading@10: if (res_val) { yading@10: int index = lpc.lpc_order - 1; yading@10: int neg = (res_val < 0); yading@10: yading@10: while (index >= 0 && (neg ? (res_val < 0) : (res_val > 0))) { yading@10: int val = samples[0] - samples[lpc.lpc_order - index]; yading@10: int sign = (val ? FFSIGN(val) : 0); yading@10: yading@10: if (neg) yading@10: sign *= -1; yading@10: yading@10: lpc.lpc_coeff[index] -= sign; yading@10: val *= sign; yading@10: res_val -= (val >> lpc.lpc_quant) * (lpc.lpc_order - index); yading@10: index--; yading@10: } yading@10: } yading@10: samples++; yading@10: } yading@10: } yading@10: } yading@10: yading@10: static void alac_entropy_coder(AlacEncodeContext *s) yading@10: { yading@10: unsigned int history = s->rc.initial_history; yading@10: int sign_modifier = 0, i, k; yading@10: int32_t *samples = s->predictor_buf; yading@10: yading@10: for (i = 0; i < s->frame_size;) { yading@10: int x; yading@10: yading@10: k = av_log2((history >> 9) + 3); yading@10: yading@10: x = -2 * (*samples) -1; yading@10: x ^= x >> 31; yading@10: yading@10: samples++; yading@10: i++; yading@10: yading@10: encode_scalar(s, x - sign_modifier, k, s->write_sample_size); yading@10: yading@10: history += x * s->rc.history_mult - yading@10: ((history * s->rc.history_mult) >> 9); yading@10: yading@10: sign_modifier = 0; yading@10: if (x > 0xFFFF) yading@10: history = 0xFFFF; yading@10: yading@10: if (history < 128 && i < s->frame_size) { yading@10: unsigned int block_size = 0; yading@10: yading@10: k = 7 - av_log2(history) + ((history + 16) >> 6); yading@10: yading@10: while (*samples == 0 && i < s->frame_size) { yading@10: samples++; yading@10: i++; yading@10: block_size++; yading@10: } yading@10: encode_scalar(s, block_size, k, 16); yading@10: sign_modifier = (block_size <= 0xFFFF); yading@10: history = 0; yading@10: } yading@10: yading@10: } yading@10: } yading@10: yading@10: static void write_element(AlacEncodeContext *s, yading@10: enum AlacRawDataBlockType element, int instance, yading@10: const uint8_t *samples0, const uint8_t *samples1) yading@10: { yading@10: uint8_t const *samples[2] = { samples0, samples1 }; yading@10: int i, j, channels; yading@10: int prediction_type = 0; yading@10: PutBitContext *pb = &s->pbctx; yading@10: yading@10: channels = element == TYPE_CPE ? 2 : 1; yading@10: yading@10: if (s->verbatim) { yading@10: write_element_header(s, element, instance); yading@10: /* samples are channel-interleaved in verbatim mode */ yading@10: if (s->avctx->sample_fmt == AV_SAMPLE_FMT_S32P) { yading@10: int shift = 32 - s->avctx->bits_per_raw_sample; yading@10: int32_t const *samples_s32[2] = { (const int32_t *)samples0, yading@10: (const int32_t *)samples1 }; yading@10: for (i = 0; i < s->frame_size; i++) yading@10: for (j = 0; j < channels; j++) yading@10: put_sbits(pb, s->avctx->bits_per_raw_sample, yading@10: samples_s32[j][i] >> shift); yading@10: } else { yading@10: int16_t const *samples_s16[2] = { (const int16_t *)samples0, yading@10: (const int16_t *)samples1 }; yading@10: for (i = 0; i < s->frame_size; i++) yading@10: for (j = 0; j < channels; j++) yading@10: put_sbits(pb, s->avctx->bits_per_raw_sample, yading@10: samples_s16[j][i]); yading@10: } yading@10: } else { yading@10: s->write_sample_size = s->avctx->bits_per_raw_sample - s->extra_bits + yading@10: channels - 1; yading@10: yading@10: init_sample_buffers(s, channels, samples); yading@10: write_element_header(s, element, instance); yading@10: yading@10: if (channels == 2) yading@10: alac_stereo_decorrelation(s); yading@10: else yading@10: s->interlacing_shift = s->interlacing_leftweight = 0; yading@10: put_bits(pb, 8, s->interlacing_shift); yading@10: put_bits(pb, 8, s->interlacing_leftweight); yading@10: yading@10: for (i = 0; i < channels; i++) { yading@10: calc_predictor_params(s, i); yading@10: yading@10: put_bits(pb, 4, prediction_type); yading@10: put_bits(pb, 4, s->lpc[i].lpc_quant); yading@10: yading@10: put_bits(pb, 3, s->rc.rice_modifier); yading@10: put_bits(pb, 5, s->lpc[i].lpc_order); yading@10: // predictor coeff. table yading@10: for (j = 0; j < s->lpc[i].lpc_order; j++) yading@10: put_sbits(pb, 16, s->lpc[i].lpc_coeff[j]); yading@10: } yading@10: yading@10: // write extra bits if needed yading@10: if (s->extra_bits) { yading@10: uint32_t mask = (1 << s->extra_bits) - 1; yading@10: for (i = 0; i < s->frame_size; i++) { yading@10: for (j = 0; j < channels; j++) { yading@10: put_bits(pb, s->extra_bits, s->sample_buf[j][i] & mask); yading@10: s->sample_buf[j][i] >>= s->extra_bits; yading@10: } yading@10: } yading@10: } yading@10: yading@10: // apply lpc and entropy coding to audio samples yading@10: for (i = 0; i < channels; i++) { yading@10: alac_linear_predictor(s, i); yading@10: yading@10: // TODO: determine when this will actually help. for now it's not used. yading@10: if (prediction_type == 15) { yading@10: // 2nd pass 1st order filter yading@10: for (j = s->frame_size - 1; j > 0; j--) yading@10: s->predictor_buf[j] -= s->predictor_buf[j - 1]; yading@10: } yading@10: alac_entropy_coder(s); yading@10: } yading@10: } yading@10: } yading@10: yading@10: static int write_frame(AlacEncodeContext *s, AVPacket *avpkt, yading@10: uint8_t * const *samples) yading@10: { yading@10: PutBitContext *pb = &s->pbctx; yading@10: const enum AlacRawDataBlockType *ch_elements = ff_alac_channel_elements[s->avctx->channels - 1]; yading@10: const uint8_t *ch_map = ff_alac_channel_layout_offsets[s->avctx->channels - 1]; yading@10: int ch, element, sce, cpe; yading@10: yading@10: init_put_bits(pb, avpkt->data, avpkt->size); yading@10: yading@10: ch = element = sce = cpe = 0; yading@10: while (ch < s->avctx->channels) { yading@10: if (ch_elements[element] == TYPE_CPE) { yading@10: write_element(s, TYPE_CPE, cpe, samples[ch_map[ch]], yading@10: samples[ch_map[ch + 1]]); yading@10: cpe++; yading@10: ch += 2; yading@10: } else { yading@10: write_element(s, TYPE_SCE, sce, samples[ch_map[ch]], NULL); yading@10: sce++; yading@10: ch++; yading@10: } yading@10: element++; yading@10: } yading@10: yading@10: put_bits(pb, 3, TYPE_END); yading@10: flush_put_bits(pb); yading@10: yading@10: return put_bits_count(pb) >> 3; yading@10: } yading@10: yading@10: static av_always_inline int get_max_frame_size(int frame_size, int ch, int bps) yading@10: { yading@10: int header_bits = 23 + 32 * (frame_size < DEFAULT_FRAME_SIZE); yading@10: return FFALIGN(header_bits + bps * ch * frame_size + 3, 8) / 8; yading@10: } yading@10: yading@10: static av_cold int alac_encode_close(AVCodecContext *avctx) yading@10: { yading@10: AlacEncodeContext *s = avctx->priv_data; yading@10: ff_lpc_end(&s->lpc_ctx); yading@10: av_freep(&avctx->extradata); yading@10: avctx->extradata_size = 0; yading@10: av_freep(&avctx->coded_frame); yading@10: return 0; yading@10: } yading@10: yading@10: static av_cold int alac_encode_init(AVCodecContext *avctx) yading@10: { yading@10: AlacEncodeContext *s = avctx->priv_data; yading@10: int ret; yading@10: uint8_t *alac_extradata; yading@10: yading@10: avctx->frame_size = s->frame_size = DEFAULT_FRAME_SIZE; yading@10: yading@10: if (avctx->sample_fmt == AV_SAMPLE_FMT_S32P) { yading@10: if (avctx->bits_per_raw_sample != 24) yading@10: av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n"); yading@10: avctx->bits_per_raw_sample = 24; yading@10: } else { yading@10: avctx->bits_per_raw_sample = 16; yading@10: s->extra_bits = 0; yading@10: } yading@10: yading@10: // Set default compression level yading@10: if (avctx->compression_level == FF_COMPRESSION_DEFAULT) yading@10: s->compression_level = 2; yading@10: else yading@10: s->compression_level = av_clip(avctx->compression_level, 0, 2); yading@10: yading@10: // Initialize default Rice parameters yading@10: s->rc.history_mult = 40; yading@10: s->rc.initial_history = 10; yading@10: s->rc.k_modifier = 14; yading@10: s->rc.rice_modifier = 4; yading@10: yading@10: s->max_coded_frame_size = get_max_frame_size(avctx->frame_size, yading@10: avctx->channels, yading@10: avctx->bits_per_raw_sample); yading@10: yading@10: avctx->extradata = av_mallocz(ALAC_EXTRADATA_SIZE + FF_INPUT_BUFFER_PADDING_SIZE); yading@10: if (!avctx->extradata) { yading@10: ret = AVERROR(ENOMEM); yading@10: goto error; yading@10: } yading@10: avctx->extradata_size = ALAC_EXTRADATA_SIZE; yading@10: yading@10: alac_extradata = avctx->extradata; yading@10: AV_WB32(alac_extradata, ALAC_EXTRADATA_SIZE); yading@10: AV_WB32(alac_extradata+4, MKBETAG('a','l','a','c')); yading@10: AV_WB32(alac_extradata+12, avctx->frame_size); yading@10: AV_WB8 (alac_extradata+17, avctx->bits_per_raw_sample); yading@10: AV_WB8 (alac_extradata+21, avctx->channels); yading@10: AV_WB32(alac_extradata+24, s->max_coded_frame_size); yading@10: AV_WB32(alac_extradata+28, yading@10: avctx->sample_rate * avctx->channels * avctx->bits_per_raw_sample); // average bitrate yading@10: AV_WB32(alac_extradata+32, avctx->sample_rate); yading@10: yading@10: // Set relevant extradata fields yading@10: if (s->compression_level > 0) { yading@10: AV_WB8(alac_extradata+18, s->rc.history_mult); yading@10: AV_WB8(alac_extradata+19, s->rc.initial_history); yading@10: AV_WB8(alac_extradata+20, s->rc.k_modifier); yading@10: } yading@10: yading@10: s->min_prediction_order = DEFAULT_MIN_PRED_ORDER; yading@10: if (avctx->min_prediction_order >= 0) { yading@10: if (avctx->min_prediction_order < MIN_LPC_ORDER || yading@10: avctx->min_prediction_order > ALAC_MAX_LPC_ORDER) { yading@10: av_log(avctx, AV_LOG_ERROR, "invalid min prediction order: %d\n", yading@10: avctx->min_prediction_order); yading@10: ret = AVERROR(EINVAL); yading@10: goto error; yading@10: } yading@10: yading@10: s->min_prediction_order = avctx->min_prediction_order; yading@10: } yading@10: yading@10: s->max_prediction_order = DEFAULT_MAX_PRED_ORDER; yading@10: if (avctx->max_prediction_order >= 0) { yading@10: if (avctx->max_prediction_order < MIN_LPC_ORDER || yading@10: avctx->max_prediction_order > ALAC_MAX_LPC_ORDER) { yading@10: av_log(avctx, AV_LOG_ERROR, "invalid max prediction order: %d\n", yading@10: avctx->max_prediction_order); yading@10: ret = AVERROR(EINVAL); yading@10: goto error; yading@10: } yading@10: yading@10: s->max_prediction_order = avctx->max_prediction_order; yading@10: } yading@10: yading@10: if (s->max_prediction_order < s->min_prediction_order) { yading@10: av_log(avctx, AV_LOG_ERROR, yading@10: "invalid prediction orders: min=%d max=%d\n", yading@10: s->min_prediction_order, s->max_prediction_order); yading@10: ret = AVERROR(EINVAL); yading@10: goto error; yading@10: } yading@10: yading@10: avctx->coded_frame = avcodec_alloc_frame(); yading@10: if (!avctx->coded_frame) { yading@10: ret = AVERROR(ENOMEM); yading@10: goto error; yading@10: } yading@10: yading@10: s->avctx = avctx; yading@10: yading@10: if ((ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size, yading@10: s->max_prediction_order, yading@10: FF_LPC_TYPE_LEVINSON)) < 0) { yading@10: goto error; yading@10: } yading@10: yading@10: return 0; yading@10: error: yading@10: alac_encode_close(avctx); yading@10: return ret; yading@10: } yading@10: yading@10: static int alac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, yading@10: const AVFrame *frame, int *got_packet_ptr) yading@10: { yading@10: AlacEncodeContext *s = avctx->priv_data; yading@10: int out_bytes, max_frame_size, ret; yading@10: yading@10: s->frame_size = frame->nb_samples; yading@10: yading@10: if (frame->nb_samples < DEFAULT_FRAME_SIZE) yading@10: max_frame_size = get_max_frame_size(s->frame_size, avctx->channels, yading@10: avctx->bits_per_raw_sample); yading@10: else yading@10: max_frame_size = s->max_coded_frame_size; yading@10: yading@10: if ((ret = ff_alloc_packet2(avctx, avpkt, 2 * max_frame_size)) < 0) yading@10: return ret; yading@10: yading@10: /* use verbatim mode for compression_level 0 */ yading@10: if (s->compression_level) { yading@10: s->verbatim = 0; yading@10: s->extra_bits = avctx->bits_per_raw_sample - 16; yading@10: } else { yading@10: s->verbatim = 1; yading@10: s->extra_bits = 0; yading@10: } yading@10: yading@10: out_bytes = write_frame(s, avpkt, frame->extended_data); yading@10: yading@10: if (out_bytes > max_frame_size) { yading@10: /* frame too large. use verbatim mode */ yading@10: s->verbatim = 1; yading@10: s->extra_bits = 0; yading@10: out_bytes = write_frame(s, avpkt, frame->extended_data); yading@10: } yading@10: yading@10: avpkt->size = out_bytes; yading@10: *got_packet_ptr = 1; yading@10: return 0; yading@10: } yading@10: yading@10: AVCodec ff_alac_encoder = { yading@10: .name = "alac", yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: .id = AV_CODEC_ID_ALAC, yading@10: .priv_data_size = sizeof(AlacEncodeContext), yading@10: .init = alac_encode_init, yading@10: .encode2 = alac_encode_frame, yading@10: .close = alac_encode_close, yading@10: .capabilities = CODEC_CAP_SMALL_LAST_FRAME, yading@10: .channel_layouts = ff_alac_channel_layouts, yading@10: .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32P, yading@10: AV_SAMPLE_FMT_S16P, yading@10: AV_SAMPLE_FMT_NONE }, yading@10: .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"), yading@10: };