--- /dev/null
+/*
+ * DV decoder
+ * Copyright (c) 2002 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 dv.c
+ * DV decoder.
+ */
+#include "avcodec.h"
+#include "dsputil.h"
+#include "mpegvideo.h"
+#include "simple_idct.h"
+
+#define NTSC_FRAME_SIZE 120000
+#define PAL_FRAME_SIZE 144000
+
+#define TEX_VLC_BITS 9
+
+typedef struct DVVideoDecodeContext {
+ AVCodecContext *avctx;
+ GetBitContext gb;
+ VLC *vlc;
+ int sampling_411; /* 0 = 420, 1 = 411 */
+ int width, height;
+ uint8_t *current_picture[3]; /* picture structure */
+ AVFrame picture;
+ int linesize[3];
+ DCTELEM block[5*6][64] __align8;
+ uint8_t dv_zigzag[2][64];
+ uint8_t idct_permutation[64];
+ /* XXX: move it to static storage ? */
+ uint8_t dv_shift[2][22][64];
+ void (*idct_put[2])(uint8_t *dest, int line_size, DCTELEM *block);
+} DVVideoDecodeContext;
+
+#include "dvdata.h"
+
+static VLC dv_vlc;
+/* XXX: also include quantization */
+static RL_VLC_ELEM *dv_rl_vlc[1];
+
+static void dv_build_unquantize_tables(DVVideoDecodeContext *s)
+{
+ int i, q, j;
+
+ /* NOTE: max left shift is 6 */
+ for(q = 0; q < 22; q++) {
+ /* 88 unquant */
+ for(i = 1; i < 64; i++) {
+ /* 88 table */
+ j = s->idct_permutation[i];
+ s->dv_shift[0][q][j] =
+ dv_quant_shifts[q][dv_88_areas[i]] + 1;
+ }
+
+ /* 248 unquant */
+ for(i = 1; i < 64; i++) {
+ /* 248 table */
+ s->dv_shift[1][q][i] =
+ dv_quant_shifts[q][dv_248_areas[i]] + 1;
+ }
+ }
+}
+
+static int dvvideo_decode_init(AVCodecContext *avctx)
+{
+ DVVideoDecodeContext *s = avctx->priv_data;
+ MpegEncContext s2;
+ static int done=0;
+
+ if (!done) {
+ int i;
+
+ done = 1;
+
+ /* NOTE: as a trick, we use the fact the no codes are unused
+ to accelerate the parsing of partial codes */
+ init_vlc(&dv_vlc, TEX_VLC_BITS, NB_DV_VLC,
+ dv_vlc_len, 1, 1, dv_vlc_bits, 2, 2);
+
+ dv_rl_vlc[0] = av_malloc(dv_vlc.table_size * sizeof(RL_VLC_ELEM));
+ for(i = 0; i < dv_vlc.table_size; i++){
+ int code= dv_vlc.table[i][0];
+ int len = dv_vlc.table[i][1];
+ int level, run;
+
+ if(len<0){ //more bits needed
+ run= 0;
+ level= code;
+ } else if (code == (NB_DV_VLC - 1)) {
+ /* EOB */
+ run = 0;
+ level = 256;
+ } else {
+ run= dv_vlc_run[code] + 1;
+ level= dv_vlc_level[code];
+ }
+ dv_rl_vlc[0][i].len = len;
+ dv_rl_vlc[0][i].level = level;
+ dv_rl_vlc[0][i].run = run;
+ }
+ }
+
+ /* ugly way to get the idct & scantable */
+ /* XXX: fix it */
+ memset(&s2, 0, sizeof(MpegEncContext));
+ s2.avctx = avctx;
+ dsputil_init(&s2.dsp, avctx);
+ if (DCT_common_init(&s2) < 0)
+ return -1;
+
+ s->idct_put[0] = s2.dsp.idct_put;
+ memcpy(s->idct_permutation, s2.dsp.idct_permutation, 64);
+ memcpy(s->dv_zigzag[0], s2.intra_scantable.permutated, 64);
+
+ /* XXX: use MMX also for idct248 */
+ s->idct_put[1] = simple_idct248_put;
+ memcpy(s->dv_zigzag[1], dv_248_zigzag, 64);
+
+ /* XXX: do it only for constant case */
+ dv_build_unquantize_tables(s);
+
+ return 0;
+}
+
+//#define VLC_DEBUG
+
+typedef struct BlockInfo {
+ const uint8_t *shift_table;
+ const uint8_t *scan_table;
+ uint8_t pos; /* position in block */
+ uint8_t eob_reached; /* true if EOB has been reached */
+ uint8_t dct_mode;
+ uint8_t partial_bit_count;
+ uint16_t partial_bit_buffer;
+ int shift_offset;
+} BlockInfo;
+
+/* block size in bits */
+static const uint16_t block_sizes[6] = {
+ 112, 112, 112, 112, 80, 80
+};
+
+#ifndef ALT_BITSTREAM_READER
+#warning only works with ALT_BITSTREAM_READER
+#endif
+
+/* decode ac coefs */
+static void dv_decode_ac(DVVideoDecodeContext *s,
+ BlockInfo *mb, DCTELEM *block, int last_index)
+{
+ int last_re_index;
+ int shift_offset = mb->shift_offset;
+ const uint8_t *scan_table = mb->scan_table;
+ const uint8_t *shift_table = mb->shift_table;
+ int pos = mb->pos;
+ int level, pos1, sign, run;
+ int partial_bit_count;
+#ifndef ALT_BITSTREAM_READER //FIXME
+ int re_index=0;
+ int re1_index=0;
+#endif
+ OPEN_READER(re, &s->gb);
+
+#ifdef VLC_DEBUG
+ printf("start\n");
+#endif
+
+ /* if we must parse a partial vlc, we do it here */
+ partial_bit_count = mb->partial_bit_count;
+ if (partial_bit_count > 0) {
+ uint8_t buf[4];
+ uint32_t v;
+ int l, l1;
+ GetBitContext gb1;
+
+ /* build the dummy bit buffer */
+ l = 16 - partial_bit_count;
+ UPDATE_CACHE(re, &s->gb);
+#ifdef VLC_DEBUG
+ printf("show=%04x\n", SHOW_UBITS(re, &s->gb, 16));
+#endif
+ v = (mb->partial_bit_buffer << l) | SHOW_UBITS(re, &s->gb, l);
+ buf[0] = v >> 8;
+ buf[1] = v;
+#ifdef VLC_DEBUG
+ printf("v=%04x cnt=%d %04x\n",
+ v, partial_bit_count, (mb->partial_bit_buffer << l));
+#endif
+ /* try to read the codeword */
+ init_get_bits(&gb1, buf, 4*8);
+ {
+ OPEN_READER(re1, &gb1);
+ UPDATE_CACHE(re1, &gb1);
+ GET_RL_VLC(level, run, re1, &gb1, dv_rl_vlc[0],
+ TEX_VLC_BITS, 2);
+ l = re1_index;
+ CLOSE_READER(re1, &gb1);
+ }
+#ifdef VLC_DEBUG
+ printf("****run=%d level=%d size=%d\n", run, level, l);
+#endif
+ /* compute codeword length */
+ l1 = (level != 256 && level != 0);
+ /* if too long, we cannot parse */
+ l -= partial_bit_count;
+ if ((re_index + l + l1) > last_index)
+ return;
+ /* skip read bits */
+ last_re_index = 0; /* avoid warning */
+ re_index += l;
+ /* by definition, if we can read the vlc, all partial bits
+ will be read (otherwise we could have read the vlc before) */
+ mb->partial_bit_count = 0;
+ UPDATE_CACHE(re, &s->gb);
+ goto handle_vlc;
+ }
+
+ /* get the AC coefficients until last_index is reached */
+ for(;;) {
+ UPDATE_CACHE(re, &s->gb);
+#ifdef VLC_DEBUG
+ printf("%2d: bits=%04x index=%d\n",
+ pos, SHOW_UBITS(re, &s->gb, 16), re_index);
+#endif
+ last_re_index = re_index;
+ GET_RL_VLC(level, run, re, &s->gb, dv_rl_vlc[0],
+ TEX_VLC_BITS, 2);
+ handle_vlc:
+#ifdef VLC_DEBUG
+ printf("run=%d level=%d\n", run, level);
+#endif
+ if (level == 256) {
+ if (re_index > last_index) {
+ cannot_read:
+ /* put position before read code */
+ re_index = last_re_index;
+ mb->eob_reached = 0;
+ break;
+ }
+ /* EOB */
+ mb->eob_reached = 1;
+ break;
+ } else if (level != 0) {
+ if ((re_index + 1) > last_index)
+ goto cannot_read;
+ sign = SHOW_SBITS(re, &s->gb, 1);
+ level = (level ^ sign) - sign;
+ LAST_SKIP_BITS(re, &s->gb, 1);
+ pos += run;
+ /* error */
+ if (pos >= 64) {
+ goto read_error;
+ }
+ pos1 = scan_table[pos];
+ level = level << (shift_table[pos1] + shift_offset);
+ block[pos1] = level;
+ // printf("run=%d level=%d shift=%d\n", run, level, shift_table[pos1]);
+ } else {
+ if (re_index > last_index)
+ goto cannot_read;
+ /* level is zero: means run without coding. No
+ sign is coded */
+ pos += run;
+ /* error */
+ if (pos >= 64) {
+ read_error:
+#if defined(VLC_DEBUG) || 1
+ fprintf(stderr, "error pos=%d\n", pos);
+#endif
+ /* for errors, we consider the eob is reached */
+ mb->eob_reached = 1;
+ break;
+ }
+ }
+ }
+ CLOSE_READER(re, &s->gb);
+ mb->pos = pos;
+}
+
+static inline void bit_copy(PutBitContext *pb, GetBitContext *gb, int bits_left)
+{
+ while (bits_left >= 16) {
+ put_bits(pb, 16, get_bits(gb, 16));
+ bits_left -= 16;
+ }
+ if (bits_left > 0) {
+ put_bits(pb, bits_left, get_bits(gb, bits_left));
+ }
+}
+
+/* mb_x and mb_y are in units of 8 pixels */
+static inline void dv_decode_video_segment(DVVideoDecodeContext *s,
+ uint8_t *buf_ptr1,
+ const uint16_t *mb_pos_ptr)
+{
+ int quant, dc, dct_mode, class1, j;
+ int mb_index, mb_x, mb_y, v, last_index;
+ DCTELEM *block, *block1;
+ int c_offset, bits_left;
+ uint8_t *y_ptr;
+ BlockInfo mb_data[5 * 6], *mb, *mb1;
+ void (*idct_put)(uint8_t *dest, int line_size, DCTELEM *block);
+ uint8_t *buf_ptr;
+ PutBitContext pb, vs_pb;
+ uint8_t mb_bit_buffer[80 + 4]; /* allow some slack */
+ int mb_bit_count;
+ uint8_t vs_bit_buffer[5 * 80 + 4]; /* allow some slack */
+ int vs_bit_count;
+
+ memset(s->block, 0, sizeof(s->block));
+
+ /* pass 1 : read DC and AC coefficients in blocks */
+ buf_ptr = buf_ptr1;
+ block1 = &s->block[0][0];
+ mb1 = mb_data;
+ init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80, NULL, NULL);
+ vs_bit_count = 0;
+ for(mb_index = 0; mb_index < 5; mb_index++) {
+ /* skip header */
+ quant = buf_ptr[3] & 0x0f;
+ buf_ptr += 4;
+ init_put_bits(&pb, mb_bit_buffer, 80, NULL, NULL);
+ mb_bit_count = 0;
+ mb = mb1;
+ block = block1;
+ for(j = 0;j < 6; j++) {
+ /* NOTE: size is not important here */
+ init_get_bits(&s->gb, buf_ptr, 14*8);
+
+ /* get the dc */
+ dc = get_bits(&s->gb, 9);
+ dc = (dc << (32 - 9)) >> (32 - 9);
+ dct_mode = get_bits1(&s->gb);
+ mb->dct_mode = dct_mode;
+ mb->scan_table = s->dv_zigzag[dct_mode];
+ class1 = get_bits(&s->gb, 2);
+ mb->shift_offset = (class1 == 3);
+ mb->shift_table = s->dv_shift[dct_mode]
+ [quant + dv_quant_offset[class1]];
+ dc = dc << 2;
+ /* convert to unsigned because 128 is not added in the
+ standard IDCT */
+ dc += 1024;
+ block[0] = dc;
+ last_index = block_sizes[j];
+ buf_ptr += last_index >> 3;
+ mb->pos = 0;
+ mb->partial_bit_count = 0;
+
+ dv_decode_ac(s, mb, block, last_index);
+
+ /* write the remaining bits in a new buffer only if the
+ block is finished */
+ bits_left = last_index - get_bits_count(&s->gb);
+ if (mb->eob_reached) {
+ mb->partial_bit_count = 0;
+ mb_bit_count += bits_left;
+ bit_copy(&pb, &s->gb, bits_left);
+ } else {
+ /* should be < 16 bits otherwise a codeword could have
+ been parsed */
+ mb->partial_bit_count = bits_left;
+ mb->partial_bit_buffer = get_bits(&s->gb, bits_left);
+ }
+ block += 64;
+ mb++;
+ }
+
+ flush_put_bits(&pb);
+
+ /* pass 2 : we can do it just after */
+#ifdef VLC_DEBUG
+ printf("***pass 2 size=%d\n", mb_bit_count);
+#endif
+ block = block1;
+ mb = mb1;
+ init_get_bits(&s->gb, mb_bit_buffer, 80*8);
+ for(j = 0;j < 6; j++) {
+ if (!mb->eob_reached && get_bits_count(&s->gb) < mb_bit_count) {
+ dv_decode_ac(s, mb, block, mb_bit_count);
+ /* if still not finished, no need to parse other blocks */
+ if (!mb->eob_reached) {
+ /* we could not parse the current AC coefficient,
+ so we add the remaining bytes */
+ bits_left = mb_bit_count - get_bits_count(&s->gb);
+ if (bits_left > 0) {
+ mb->partial_bit_count += bits_left;
+ mb->partial_bit_buffer =
+ (mb->partial_bit_buffer << bits_left) |
+ get_bits(&s->gb, bits_left);
+ }
+ goto next_mb;
+ }
+ }
+ block += 64;
+ mb++;
+ }
+ /* all blocks are finished, so the extra bytes can be used at
+ the video segment level */
+ bits_left = mb_bit_count - get_bits_count(&s->gb);
+ vs_bit_count += bits_left;
+ bit_copy(&vs_pb, &s->gb, bits_left);
+ next_mb:
+ mb1 += 6;
+ block1 += 6 * 64;
+ }
+
+ /* we need a pass other the whole video segment */
+ flush_put_bits(&vs_pb);
+
+#ifdef VLC_DEBUG
+ printf("***pass 3 size=%d\n", vs_bit_count);
+#endif
+ block = &s->block[0][0];
+ mb = mb_data;
+ init_get_bits(&s->gb, vs_bit_buffer, 5 * 80*8);
+ for(mb_index = 0; mb_index < 5; mb_index++) {
+ for(j = 0;j < 6; j++) {
+ if (!mb->eob_reached) {
+#ifdef VLC_DEBUG
+ printf("start %d:%d\n", mb_index, j);
+#endif
+ dv_decode_ac(s, mb, block, vs_bit_count);
+ }
+ block += 64;
+ mb++;
+ }
+ }
+
+ /* compute idct and place blocks */
+ block = &s->block[0][0];
+ mb = mb_data;
+ for(mb_index = 0; mb_index < 5; mb_index++) {
+ v = *mb_pos_ptr++;
+ mb_x = v & 0xff;
+ mb_y = v >> 8;
+ y_ptr = s->current_picture[0] + (mb_y * s->linesize[0] * 8) + (mb_x * 8);
+ if (s->sampling_411)
+ c_offset = (mb_y * s->linesize[1] * 8) + ((mb_x >> 2) * 8);
+ else
+ c_offset = ((mb_y >> 1) * s->linesize[1] * 8) + ((mb_x >> 1) * 8);
+ for(j = 0;j < 6; j++) {
+ idct_put = s->idct_put[mb->dct_mode];
+ if (j < 4) {
+ if (s->sampling_411 && mb_x < (704 / 8)) {
+ /* NOTE: at end of line, the macroblock is handled as 420 */
+ idct_put(y_ptr + (j * 8), s->linesize[0], block);
+ } else {
+ idct_put(y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->linesize[0]),
+ s->linesize[0], block);
+ }
+ } else {
+ if (s->sampling_411 && mb_x >= (704 / 8)) {
+ uint8_t pixels[64], *c_ptr, *c_ptr1, *ptr;
+ int y, linesize;
+ /* NOTE: at end of line, the macroblock is handled as 420 */
+ idct_put(pixels, 8, block);
+ linesize = s->linesize[6 - j];
+ c_ptr = s->current_picture[6 - j] + c_offset;
+ ptr = pixels;
+ for(y = 0;y < 8; y++) {
+ /* convert to 411P */
+ c_ptr1 = c_ptr + 8*linesize;
+ c_ptr[0]= ptr[0]; c_ptr1[0]= ptr[4];
+ c_ptr[1]= ptr[1]; c_ptr1[1]= ptr[5];
+ c_ptr[2]= ptr[2]; c_ptr1[2]= ptr[6];
+ c_ptr[3]= ptr[3]; c_ptr1[3]= ptr[7];
+ c_ptr += linesize;
+ ptr += 8;
+ }
+ } else {
+ /* don't ask me why they inverted Cb and Cr ! */
+ idct_put(s->current_picture[6 - j] + c_offset,
+ s->linesize[6 - j], block);
+ }
+ }
+ block += 64;
+ mb++;
+ }
+ }
+}
+
+
+/* NOTE: exactly one frame must be given (120000 bytes for NTSC,
+ 144000 bytes for PAL) */
+static int dvvideo_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ uint8_t *buf, int buf_size)
+{
+ DVVideoDecodeContext *s = avctx->priv_data;
+ int sct, dsf, apt, ds, nb_dif_segs, vs, width, height, i, packet_size;
+ uint8_t *buf_ptr;
+ const uint16_t *mb_pos_ptr;
+
+ /* parse id */
+ init_get_bits(&s->gb, buf, buf_size*8);
+ sct = get_bits(&s->gb, 3);
+ if (sct != 0)
+ return -1;
+ skip_bits(&s->gb, 5);
+ get_bits(&s->gb, 4); /* dsn (sequence number */
+ get_bits(&s->gb, 1); /* fsc (channel number) */
+ skip_bits(&s->gb, 3);
+ get_bits(&s->gb, 8); /* dbn (diff block number 0-134) */
+
+ dsf = get_bits(&s->gb, 1); /* 0 = NTSC 1 = PAL */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1;
+ skip_bits(&s->gb, 11);
+ apt = get_bits(&s->gb, 3); /* apt */
+
+ get_bits(&s->gb, 1); /* tf1 */
+ skip_bits(&s->gb, 4);
+ get_bits(&s->gb, 3); /* ap1 */
+
+ get_bits(&s->gb, 1); /* tf2 */
+ skip_bits(&s->gb, 4);
+ get_bits(&s->gb, 3); /* ap2 */
+
+ get_bits(&s->gb, 1); /* tf3 */
+ skip_bits(&s->gb, 4);
+ get_bits(&s->gb, 3); /* ap3 */
+
+ /* init size */
+ width = 720;
+ if (dsf) {
+ avctx->frame_rate = 25;
+ avctx->frame_rate_base = 1;
+ packet_size = PAL_FRAME_SIZE;
+ height = 576;
+ nb_dif_segs = 12;
+ } else {
+ avctx->frame_rate = 30000;
+ avctx->frame_rate_base = 1001;
+ packet_size = NTSC_FRAME_SIZE;
+ height = 480;
+ nb_dif_segs = 10;
+ }
+ /* NOTE: we only accept several full frames */
+ if (buf_size < packet_size)
+ return -1;
+
+ /* NTSC[dsf == 0] is always 720x480, 4:1:1
+ * PAL[dsf == 1] is always 720x576, 4:2:0 for IEC 68134[apt == 0]
+ * but for the SMPTE 314M[apt == 1] it is 720x576, 4:1:1
+ */
+ s->sampling_411 = !dsf || apt;
+ if (s->sampling_411) {
+ mb_pos_ptr = dsf ? dv_place_411P : dv_place_411;
+ avctx->pix_fmt = PIX_FMT_YUV411P;
+ } else {
+ mb_pos_ptr = dv_place_420;
+ avctx->pix_fmt = PIX_FMT_YUV420P;
+ }
+
+ avctx->width = width;
+ avctx->height = height;
+
+ /* Once again, this is pretty complicated by the fact that the same
+ * field is used differently by IEC 68134[apt == 0] and
+ * SMPTE 314M[apt == 1].
+ */
+ if (buf[VAUX_TC61_OFFSET] == 0x61 &&
+ ((apt == 0 && (buf[VAUX_TC61_OFFSET + 2] & 0x07) == 0x07) ||
+ (apt == 1 && (buf[VAUX_TC61_OFFSET + 2] & 0x07) == 0x02)))
+ avctx->aspect_ratio = 16.0 / 9.0;
+ else
+ avctx->aspect_ratio = 4.0 / 3.0;
+
+ if(s->picture.data[0])
+ avctx->release_buffer(avctx, &s->picture);
+
+ s->picture.reference= 0;
+ if(avctx->get_buffer(avctx, &s->picture) < 0) {
+ fprintf(stderr, "get_buffer() failed\n");
+ return -1;
+ }
+
+ for(i=0;i<3;i++) {
+ s->current_picture[i] = s->picture.data[i];
+ s->linesize[i] = s->picture.linesize[i];
+ if (!s->current_picture[i])
+ return -1;
+ }
+ s->width = width;
+ s->height = height;
+
+ /* for each DIF segment */
+ buf_ptr = buf;
+ for (ds = 0; ds < nb_dif_segs; ds++) {
+ buf_ptr += 6 * 80; /* skip DIF segment header */
+
+ for(vs = 0; vs < 27; vs++) {
+ if ((vs % 3) == 0) {
+ /* skip audio block */
+ buf_ptr += 80;
+ }
+ dv_decode_video_segment(s, buf_ptr, mb_pos_ptr);
+ buf_ptr += 5 * 80;
+ mb_pos_ptr += 5;
+ }
+ }
+
+ emms_c();
+
+ /* return image */
+ *data_size = sizeof(AVFrame);
+ *(AVFrame*)data= s->picture;
+
+ return packet_size;
+}
+
+static int dvvideo_decode_end(AVCodecContext *avctx)
+{
+ avcodec_default_free_buffers(avctx);
+
+ return 0;
+}
+
+AVCodec dvvideo_decoder = {
+ "dvvideo",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_DVVIDEO,
+ sizeof(DVVideoDecodeContext),
+ dvvideo_decode_init,
+ NULL,
+ dvvideo_decode_end,
+ dvvideo_decode_frame,
+ CODEC_CAP_DR1,
+ NULL
+};
+
+typedef struct DVAudioDecodeContext {
+ AVCodecContext *avctx;
+ GetBitContext gb;
+} DVAudioDecodeContext;
+
+static int dvaudio_decode_init(AVCodecContext *avctx)
+{
+ // DVAudioDecodeContext *s = avctx->priv_data;
+ return 0;
+}
+
+static uint16_t dv_audio_12to16(uint16_t sample)
+{
+ uint16_t shift, result;
+
+ sample = (sample < 0x800) ? sample : sample | 0xf000;
+ shift = (sample & 0xf00) >> 8;
+
+ if (shift < 0x2 || shift > 0xd) {
+ result = sample;
+ } else if (shift < 0x8) {
+ shift--;
+ result = (sample - (256 * shift)) << shift;
+ } else {
+ shift = 0xe - shift;
+ result = ((sample + ((256 * shift) + 1)) << shift) - 1;
+ }
+
+ return result;
+}
+
+/* NOTE: exactly one frame must be given (120000 bytes for NTSC,
+ 144000 bytes for PAL)
+
+ There's a couple of assumptions being made here:
+ 1. By default we silence erroneous (0x8000/16bit 0x800/12bit)
+ audio samples. We can pass them upwards when ffmpeg will be ready
+ to deal with them.
+ 2. We don't do software emphasis.
+ 3. Audio is always returned as 16bit linear samples: 12bit
+ nonlinear samples are converted into 16bit linear ones.
+*/
+static int dvaudio_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ uint8_t *buf, int buf_size)
+{
+ DVVideoDecodeContext *s = avctx->priv_data;
+ const uint16_t (*unshuffle)[9];
+ int smpls, freq, quant, sys, stride, difseg, ad, dp, nb_dif_segs, i;
+ uint16_t lc, rc;
+ uint8_t *buf_ptr;
+
+ /* parse id */
+ init_get_bits(&s->gb, &buf[AAUX_AS_OFFSET], 5*8);
+ i = get_bits(&s->gb, 8);
+ if (i != 0x50) { /* No audio ? */
+ *data_size = 0;
+ return buf_size;
+ }
+
+ get_bits(&s->gb, 1); /* 0 - locked audio, 1 - unlocked audio */
+ skip_bits(&s->gb, 1);
+ smpls = get_bits(&s->gb, 6); /* samples in this frame - min. samples */
+
+ skip_bits(&s->gb, 8);
+
+ skip_bits(&s->gb, 2);
+ sys = get_bits(&s->gb, 1); /* 0 - 60 fields, 1 = 50 fields */
+ skip_bits(&s->gb, 5);
+
+ get_bits(&s->gb, 1); /* 0 - emphasis on, 1 - emphasis off */
+ get_bits(&s->gb, 1); /* 0 - reserved, 1 - emphasis time constant 50/15us */
+ freq = get_bits(&s->gb, 3); /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
+ quant = get_bits(&s->gb, 3); /* 0 - 16bit linear, 1 - 12bit nonlinear */
+
+ if (quant > 1)
+ return -1; /* Unsupported quantization */
+
+ avctx->sample_rate = dv_audio_frequency[freq];
+ avctx->channels = 2;
+ avctx->bit_rate = avctx->channels * avctx->sample_rate * 16;
+ // What about:
+ // avctx->frame_size =
+
+ *data_size = (dv_audio_min_samples[sys][freq] + smpls) *
+ avctx->channels * 2;
+
+ if (sys) {
+ nb_dif_segs = 12;
+ stride = 108;
+ unshuffle = dv_place_audio50;
+ } else {
+ nb_dif_segs = 10;
+ stride = 90;
+ unshuffle = dv_place_audio60;
+ }
+
+ /* for each DIF segment */
+ buf_ptr = buf;
+ for (difseg = 0; difseg < nb_dif_segs; difseg++) {
+ buf_ptr += 6 * 80; /* skip DIF segment header */
+ for (ad = 0; ad < 9; ad++) {
+
+ for (dp = 8; dp < 80; dp+=2) {
+ if (quant == 0) { /* 16bit quantization */
+ i = unshuffle[difseg][ad] + (dp - 8)/2 * stride;
+ ((short *)data)[i] = (buf_ptr[dp] << 8) | buf_ptr[dp+1];
+ if (((unsigned short *)data)[i] == 0x8000)
+ ((short *)data)[i] = 0;
+ } else { /* 12bit quantization */
+ if (difseg >= nb_dif_segs/2)
+ goto out; /* We're not doing 4ch at this time */
+
+ lc = ((uint16_t)buf_ptr[dp] << 4) |
+ ((uint16_t)buf_ptr[dp+2] >> 4);
+ rc = ((uint16_t)buf_ptr[dp+1] << 4) |
+ ((uint16_t)buf_ptr[dp+2] & 0x0f);
+ lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
+ rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
+
+ i = unshuffle[difseg][ad] + (dp - 8)/3 * stride;
+ ((short *)data)[i] = lc;
+ i = unshuffle[difseg+nb_dif_segs/2][ad] + (dp - 8)/3 * stride;
+ ((short *)data)[i] = rc;
+ ++dp;
+ }
+ }
+
+ buf_ptr += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
+ }
+ }
+
+out:
+ return buf_size;
+}
+
+static int dvaudio_decode_end(AVCodecContext *avctx)
+{
+ // DVAudioDecodeContext *s = avctx->priv_data;
+ return 0;
+}
+
+AVCodec dvaudio_decoder = {
+ "dvaudio",
+ CODEC_TYPE_AUDIO,
+ CODEC_ID_DVAUDIO,
+ sizeof(DVAudioDecodeContext),
+ dvaudio_decode_init,
+ NULL,
+ dvaudio_decode_end,
+ dvaudio_decode_frame,
+ 0,
+ NULL
+};
projects / synfig.git / blobdiff