3 * Copyright (c) 2005 Jeff Muizelaar
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * @author Jeff Muizelaar
31 #include "bytestream.h"
36 #define MAX_CHANNELS 8
37 #define MAX_BLOCKSIZE 65535
39 #define OUT_BUFFER_SIZE 16384
43 #define WAVE_FORMAT_PCM 0x0001
45 #define DEFAULT_BLOCK_SIZE 256
51 #define BITSHIFTSIZE 2
64 #define V2LPCQOFFSET (1 << LPCQUANT)
72 #define FN_BLOCKSIZE 5
78 /** indicates if the FN_* command is audio or non-audio */
79 static const uint8_t is_audio_command[10] = { 1, 1, 1, 1, 0, 0, 0, 1, 1, 0 };
81 #define VERBATIM_CKSIZE_SIZE 5
82 #define VERBATIM_BYTE_SIZE 8
83 #define CANONICAL_HEADER_SIZE 44
85 typedef struct ShortenContext {
86 AVCodecContext *avctx;
89 int min_framesize, max_framesize;
92 int32_t *decoded[MAX_CHANNELS];
93 int32_t *decoded_base[MAX_CHANNELS];
94 int32_t *offset[MAX_CHANNELS];
99 unsigned int allocated_bitstream_size;
101 uint8_t header[OUT_BUFFER_SIZE];
112 int got_quit_command;
115 static av_cold int shorten_decode_init(AVCodecContext *avctx)
117 ShortenContext *s = avctx->priv_data;
123 static int allocate_buffers(ShortenContext *s)
129 for (chan = 0; chan < s->channels; chan++) {
130 if (FFMAX(1, s->nmean) >= UINT_MAX / sizeof(int32_t)) {
131 av_log(s->avctx, AV_LOG_ERROR, "nmean too large\n");
132 return AVERROR_INVALIDDATA;
134 if (s->blocksize + s->nwrap >= UINT_MAX / sizeof(int32_t) ||
135 s->blocksize + s->nwrap <= (unsigned)s->nwrap) {
136 av_log(s->avctx, AV_LOG_ERROR,
137 "s->blocksize + s->nwrap too large\n");
138 return AVERROR_INVALIDDATA;
142 av_realloc(s->offset[chan], sizeof(int32_t) * FFMAX(1, s->nmean));
144 return AVERROR(ENOMEM);
145 s->offset[chan] = tmp_ptr;
147 tmp_ptr = av_realloc(s->decoded_base[chan], (s->blocksize + s->nwrap) *
148 sizeof(s->decoded_base[0][0]));
150 return AVERROR(ENOMEM);
151 s->decoded_base[chan] = tmp_ptr;
152 for (i = 0; i < s->nwrap; i++)
153 s->decoded_base[chan][i] = 0;
154 s->decoded[chan] = s->decoded_base[chan] + s->nwrap;
157 coeffs = av_realloc(s->coeffs, s->nwrap * sizeof(*s->coeffs));
159 return AVERROR(ENOMEM);
165 static inline unsigned int get_uint(ShortenContext *s, int k)
168 k = get_ur_golomb_shorten(&s->gb, ULONGSIZE);
169 return get_ur_golomb_shorten(&s->gb, k);
172 static void fix_bitshift(ShortenContext *s, int32_t *buffer)
176 if (s->bitshift != 0)
177 for (i = 0; i < s->blocksize; i++)
178 buffer[i] <<= s->bitshift;
181 static int init_offset(ShortenContext *s)
185 int nblock = FFMAX(1, s->nmean);
186 /* initialise offset */
187 switch (s->internal_ftype) {
189 s->avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
194 s->avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
197 av_log(s->avctx, AV_LOG_ERROR, "unknown audio type\n");
198 return AVERROR_PATCHWELCOME;
201 for (chan = 0; chan < s->channels; chan++)
202 for (i = 0; i < nblock; i++)
203 s->offset[chan][i] = mean;
207 static int decode_wave_header(AVCodecContext *avctx, const uint8_t *header,
214 bytestream2_init(&gb, header, header_size);
216 if (bytestream2_get_le32(&gb) != MKTAG('R', 'I', 'F', 'F')) {
217 av_log(avctx, AV_LOG_ERROR, "missing RIFF tag\n");
218 return AVERROR_INVALIDDATA;
221 bytestream2_skip(&gb, 4); /* chunk size */
223 if (bytestream2_get_le32(&gb) != MKTAG('W', 'A', 'V', 'E')) {
224 av_log(avctx, AV_LOG_ERROR, "missing WAVE tag\n");
225 return AVERROR_INVALIDDATA;
228 while (bytestream2_get_le32(&gb) != MKTAG('f', 'm', 't', ' ')) {
229 len = bytestream2_get_le32(&gb);
230 bytestream2_skip(&gb, len);
231 if (len < 0 || bytestream2_get_bytes_left(&gb) < 16) {
232 av_log(avctx, AV_LOG_ERROR, "no fmt chunk found\n");
233 return AVERROR_INVALIDDATA;
236 len = bytestream2_get_le32(&gb);
239 av_log(avctx, AV_LOG_ERROR, "fmt chunk was too short\n");
240 return AVERROR_INVALIDDATA;
243 wave_format = bytestream2_get_le16(&gb);
245 switch (wave_format) {
246 case WAVE_FORMAT_PCM:
249 av_log(avctx, AV_LOG_ERROR, "unsupported wave format\n");
250 return AVERROR(ENOSYS);
253 bytestream2_skip(&gb, 2); // skip channels (already got from shorten header)
254 avctx->sample_rate = bytestream2_get_le32(&gb);
255 bytestream2_skip(&gb, 4); // skip bit rate (represents original uncompressed bit rate)
256 bytestream2_skip(&gb, 2); // skip block align (not needed)
257 bps = bytestream2_get_le16(&gb);
258 avctx->bits_per_coded_sample = bps;
260 if (bps != 16 && bps != 8) {
261 av_log(avctx, AV_LOG_ERROR, "unsupported number of bits per sample: %d\n", bps);
262 return AVERROR(ENOSYS);
267 av_log(avctx, AV_LOG_INFO, "%d header bytes unparsed\n", len);
272 static const int fixed_coeffs[][3] = {
279 static int decode_subframe_lpc(ShortenContext *s, int command, int channel,
280 int residual_size, int32_t coffset)
282 int pred_order, sum, qshift, init_sum, i, j;
285 if (command == FN_QLPC) {
286 /* read/validate prediction order */
287 pred_order = get_ur_golomb_shorten(&s->gb, LPCQSIZE);
288 if (pred_order > s->nwrap) {
289 av_log(s->avctx, AV_LOG_ERROR, "invalid pred_order %d\n",
291 return AVERROR(EINVAL);
293 /* read LPC coefficients */
294 for (i = 0; i < pred_order; i++)
295 s->coeffs[i] = get_sr_golomb_shorten(&s->gb, LPCQUANT);
300 /* fixed LPC coeffs */
301 pred_order = command;
302 if (pred_order >= FF_ARRAY_ELEMS(fixed_coeffs)) {
303 av_log(s->avctx, AV_LOG_ERROR, "invalid pred_order %d\n",
305 return AVERROR_INVALIDDATA;
307 coeffs = fixed_coeffs[pred_order];
311 /* subtract offset from previous samples to use in prediction */
312 if (command == FN_QLPC && coffset)
313 for (i = -pred_order; i < 0; i++)
314 s->decoded[channel][i] -= coffset;
316 /* decode residual and do LPC prediction */
317 init_sum = pred_order ? (command == FN_QLPC ? s->lpcqoffset : 0) : coffset;
318 for (i = 0; i < s->blocksize; i++) {
320 for (j = 0; j < pred_order; j++)
321 sum += coeffs[j] * s->decoded[channel][i - j - 1];
322 s->decoded[channel][i] = get_sr_golomb_shorten(&s->gb, residual_size) +
326 /* add offset to current samples */
327 if (command == FN_QLPC && coffset)
328 for (i = 0; i < s->blocksize; i++)
329 s->decoded[channel][i] += coffset;
334 static int read_header(ShortenContext *s)
338 /* shorten signature */
339 if (get_bits_long(&s->gb, 32) != AV_RB32("ajkg")) {
340 av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n");
341 return AVERROR_INVALIDDATA;
345 s->blocksize = DEFAULT_BLOCK_SIZE;
347 s->version = get_bits(&s->gb, 8);
348 s->internal_ftype = get_uint(s, TYPESIZE);
350 s->channels = get_uint(s, CHANSIZE);
352 av_log(s->avctx, AV_LOG_ERROR, "No channels reported\n");
353 return AVERROR_INVALIDDATA;
355 if (s->channels > MAX_CHANNELS) {
356 av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels);
358 return AVERROR_INVALIDDATA;
360 s->avctx->channels = s->channels;
362 /* get blocksize if version > 0 */
363 if (s->version > 0) {
367 blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE));
368 if (!blocksize || blocksize > MAX_BLOCKSIZE) {
369 av_log(s->avctx, AV_LOG_ERROR,
370 "invalid or unsupported block size: %d\n",
372 return AVERROR(EINVAL);
374 s->blocksize = blocksize;
376 maxnlpc = get_uint(s, LPCQSIZE);
377 s->nmean = get_uint(s, 0);
379 skip_bytes = get_uint(s, NSKIPSIZE);
380 for (i = 0; i < skip_bytes; i++)
381 skip_bits(&s->gb, 8);
383 s->nwrap = FFMAX(NWRAP, maxnlpc);
385 if ((ret = allocate_buffers(s)) < 0)
388 if ((ret = init_offset(s)) < 0)
392 s->lpcqoffset = V2LPCQOFFSET;
394 if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) {
395 av_log(s->avctx, AV_LOG_ERROR,
396 "missing verbatim section at beginning of stream\n");
397 return AVERROR_INVALIDDATA;
400 s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
401 if (s->header_size >= OUT_BUFFER_SIZE ||
402 s->header_size < CANONICAL_HEADER_SIZE) {
403 av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n",
405 return AVERROR_INVALIDDATA;
408 for (i = 0; i < s->header_size; i++)
409 s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
411 if ((ret = decode_wave_header(s->avctx, s->header, s->header_size)) < 0)
422 static int shorten_decode_frame(AVCodecContext *avctx, void *data,
423 int *got_frame_ptr, AVPacket *avpkt)
425 AVFrame *frame = data;
426 const uint8_t *buf = avpkt->data;
427 int buf_size = avpkt->size;
428 ShortenContext *s = avctx->priv_data;
429 int i, input_buf_size = 0;
432 /* allocate internal bitstream buffer */
433 if (s->max_framesize == 0) {
435 s->max_framesize = 8192; // should hopefully be enough for the first header
436 tmp_ptr = av_fast_realloc(s->bitstream, &s->allocated_bitstream_size,
437 s->max_framesize + FF_INPUT_BUFFER_PADDING_SIZE);
439 av_log(avctx, AV_LOG_ERROR, "error allocating bitstream buffer\n");
440 return AVERROR(ENOMEM);
442 s->bitstream = tmp_ptr;
445 /* append current packet data to bitstream buffer */
446 if (1 && s->max_framesize) { //FIXME truncated
447 buf_size = FFMIN(buf_size, s->max_framesize - s->bitstream_size);
448 input_buf_size = buf_size;
450 if (s->bitstream_index + s->bitstream_size + buf_size + FF_INPUT_BUFFER_PADDING_SIZE >
451 s->allocated_bitstream_size) {
452 memmove(s->bitstream, &s->bitstream[s->bitstream_index],
454 s->bitstream_index = 0;
457 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf,
459 buf = &s->bitstream[s->bitstream_index];
460 buf_size += s->bitstream_size;
461 s->bitstream_size = buf_size;
463 /* do not decode until buffer has at least max_framesize bytes or
464 * the end of the file has been reached */
465 if (buf_size < s->max_framesize && avpkt->data) {
467 return input_buf_size;
470 /* init and position bitstream reader */
471 init_get_bits(&s->gb, buf, buf_size * 8);
472 skip_bits(&s->gb, s->bitindex);
474 /* process header or next subblock */
475 if (!s->got_header) {
476 if ((ret = read_header(s)) < 0)
482 /* if quit command was read previously, don't decode anything */
483 if (s->got_quit_command) {
489 while (s->cur_chan < s->channels) {
493 if (get_bits_left(&s->gb) < 3 + FNSIZE) {
498 cmd = get_ur_golomb_shorten(&s->gb, FNSIZE);
500 if (cmd > FN_VERBATIM) {
501 av_log(avctx, AV_LOG_ERROR, "unknown shorten function %d\n", cmd);
506 if (!is_audio_command[cmd]) {
507 /* process non-audio command */
510 len = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE);
512 get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE);
515 s->bitshift = get_ur_golomb_shorten(&s->gb, BITSHIFTSIZE);
518 unsigned blocksize = get_uint(s, av_log2(s->blocksize));
519 if (blocksize > s->blocksize) {
520 av_log(avctx, AV_LOG_ERROR,
521 "Increasing block size is not supported\n");
522 return AVERROR_PATCHWELCOME;
524 if (!blocksize || blocksize > MAX_BLOCKSIZE) {
525 av_log(avctx, AV_LOG_ERROR, "invalid or unsupported "
526 "block size: %d\n", blocksize);
527 return AVERROR(EINVAL);
529 s->blocksize = blocksize;
533 s->got_quit_command = 1;
536 if (cmd == FN_BLOCKSIZE || cmd == FN_QUIT) {
541 /* process audio command */
542 int residual_size = 0;
543 int channel = s->cur_chan;
546 /* get Rice code for residual decoding */
547 if (cmd != FN_ZERO) {
548 residual_size = get_ur_golomb_shorten(&s->gb, ENERGYSIZE);
549 /* This is a hack as version 0 differed in the definition
550 * of get_sr_golomb_shorten(). */
555 /* calculate sample offset using means from previous blocks */
557 coffset = s->offset[channel][0];
559 int32_t sum = (s->version < 2) ? 0 : s->nmean / 2;
560 for (i = 0; i < s->nmean; i++)
561 sum += s->offset[channel][i];
562 coffset = sum / s->nmean;
564 coffset = s->bitshift == 0 ? coffset : coffset >> s->bitshift - 1 >> 1;
567 /* decode samples for this channel */
568 if (cmd == FN_ZERO) {
569 for (i = 0; i < s->blocksize; i++)
570 s->decoded[channel][i] = 0;
572 if ((ret = decode_subframe_lpc(s, cmd, channel,
573 residual_size, coffset)) < 0)
577 /* update means with info from the current block */
579 int32_t sum = (s->version < 2) ? 0 : s->blocksize / 2;
580 for (i = 0; i < s->blocksize; i++)
581 sum += s->decoded[channel][i];
583 for (i = 1; i < s->nmean; i++)
584 s->offset[channel][i - 1] = s->offset[channel][i];
587 s->offset[channel][s->nmean - 1] = sum / s->blocksize;
589 s->offset[channel][s->nmean - 1] = (sum / s->blocksize) << s->bitshift;
592 /* copy wrap samples for use with next block */
593 for (i = -s->nwrap; i < 0; i++)
594 s->decoded[channel][i] = s->decoded[channel][i + s->blocksize];
596 /* shift samples to add in unused zero bits which were removed
598 fix_bitshift(s, s->decoded[channel]);
600 /* if this is the last channel in the block, output the samples */
602 if (s->cur_chan == s->channels) {
604 int16_t *samples_s16;
607 /* get output buffer */
608 frame->nb_samples = s->blocksize;
609 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
612 for (chan = 0; chan < s->channels; chan++) {
613 samples_u8 = ((uint8_t **)frame->extended_data)[chan];
614 samples_s16 = ((int16_t **)frame->extended_data)[chan];
615 for (i = 0; i < s->blocksize; i++) {
616 switch (s->internal_ftype) {
618 *samples_u8++ = av_clip_uint8(s->decoded[chan][i]);
622 *samples_s16++ = av_clip_int16(s->decoded[chan][i]);
632 if (s->cur_chan < s->channels)
636 s->bitindex = get_bits_count(&s->gb) - 8 * (get_bits_count(&s->gb) / 8);
637 i = get_bits_count(&s->gb) / 8;
639 av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size);
640 s->bitstream_size = 0;
641 s->bitstream_index = 0;
642 return AVERROR_INVALIDDATA;
644 if (s->bitstream_size) {
645 s->bitstream_index += i;
646 s->bitstream_size -= i;
647 return input_buf_size;
652 static av_cold int shorten_decode_close(AVCodecContext *avctx)
654 ShortenContext *s = avctx->priv_data;
657 for (i = 0; i < s->channels; i++) {
658 s->decoded[i] = NULL;
659 av_freep(&s->decoded_base[i]);
660 av_freep(&s->offset[i]);
662 av_freep(&s->bitstream);
663 av_freep(&s->coeffs);
668 AVCodec ff_shorten_decoder = {
670 .long_name = NULL_IF_CONFIG_SMALL("Shorten"),
671 .type = AVMEDIA_TYPE_AUDIO,
672 .id = AV_CODEC_ID_SHORTEN,
673 .priv_data_size = sizeof(ShortenContext),
674 .init = shorten_decode_init,
675 .close = shorten_decode_close,
676 .decode = shorten_decode_frame,
677 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_DR1,
678 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
680 AV_SAMPLE_FMT_NONE },