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/*
* IEC 61937 muxer
* Copyright (c) 2009 Bartlomiej Wolowiec
* Copyright (c) 2010 Anssi Hannula
* Copyright (c) 2010 Carl Eugen Hoyos
*
* 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
*/
/**
* @file
* IEC-61937 encapsulation of various formats, used by S/PDIF
* @author Bartlomiej Wolowiec
* @author Anssi Hannula
* @author Carl Eugen Hoyos
*/
/*
* Terminology used in specification:
* data-burst - IEC61937 frame, contains header and encapsuled frame
* burst-preambule - IEC61937 frame header, contains 16-bits words named Pa, Pb, Pc and Pd
* burst-payload - encapsuled frame
* Pa, Pb - syncword - 0xF872, 0x4E1F
* Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)
* and bitstream number (bits 13-15)
* data-type - determines type of encapsuled frames
* Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)
*
* IEC 61937 frames at normal usage start every specific count of bytes,
* dependent from data-type (spaces between packets are filled by zeros)
*/
#include "avformat.h"
#include "avio_internal.h"
#include "spdif.h"
#include "libavcodec/ac3.h"
#include "libavcodec/dca.h"
#include "libavcodec/aacadtsdec.h"
#include "libavutil/opt.h"
typedef struct IEC61937Context {
const AVClass *av_class;
enum IEC61937DataType data_type;///< burst info - reference to type of payload of the data-burst
int length_code; ///< length code in bits or bytes, depending on data type
int pkt_offset; ///< data burst repetition period in bytes
uint8_t *buffer; ///< allocated buffer, used for swap bytes
int buffer_size; ///< size of allocated buffer
uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping
int out_bytes; ///< amount of outgoing bytes
int use_preamble; ///< preamble enabled (disabled for exactly pre-padded DTS)
int extra_bswap; ///< extra bswap for payload (for LE DTS => standard BE DTS)
uint8_t *hd_buf; ///< allocated buffer to concatenate hd audio frames
int hd_buf_size; ///< size of the hd audio buffer
int hd_buf_count; ///< number of frames in the hd audio buffer
int hd_buf_filled; ///< amount of bytes in the hd audio buffer
int dtshd_skip; ///< counter used for skipping DTS-HD frames
/* AVOptions: */
int dtshd_rate;
int dtshd_fallback;
#define SPDIF_FLAG_BIGENDIAN 0x01
int spdif_flags;
/// function, which generates codec dependent header information.
/// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary
int (*header_info) (AVFormatContext *s, AVPacket *pkt);
} IEC61937Context;
static const AVOption options[] = {
{ "spdif_flags", "IEC 61937 encapsulation flags", offsetof(IEC61937Context, spdif_flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" },
{ "be", "output in big-endian format (for use as s16be)", 0, AV_OPT_TYPE_CONST, {.i64 = SPDIF_FLAG_BIGENDIAN}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" },
{ "dtshd_rate", "mux complete DTS frames in HD mode at the specified IEC958 rate (in Hz, default 0=disabled)", offsetof(IEC61937Context, dtshd_rate), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 768000, AV_OPT_FLAG_ENCODING_PARAM },
{ "dtshd_fallback_time", "min secs to strip HD for after an overflow (-1: till the end, default 60)", offsetof(IEC61937Context, dtshd_fallback), AV_OPT_TYPE_INT, {.i64 = 60}, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ NULL },
};
static const AVClass spdif_class = {
.class_name = "spdif",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
int bitstream_mode = pkt->data[5] & 0x7;
ctx->data_type = IEC61937_AC3 | (bitstream_mode << 8);
ctx->pkt_offset = AC3_FRAME_SIZE << 2;
return 0;
}
static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
static const uint8_t eac3_repeat[4] = {6, 3, 2, 1};
int repeat = 1;
if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */
repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */
ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size);
if (!ctx->hd_buf)
return AVERROR(ENOMEM);
memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size);
ctx->hd_buf_filled += pkt->size;
if (++ctx->hd_buf_count < repeat){
ctx->pkt_offset = 0;
return 0;
}
ctx->data_type = IEC61937_EAC3;
ctx->pkt_offset = 24576;
ctx->out_buf = ctx->hd_buf;
ctx->out_bytes = ctx->hd_buf_filled;
ctx->length_code = ctx->hd_buf_filled;
ctx->hd_buf_count = 0;
ctx->hd_buf_filled = 0;
return 0;
}
/*
* DTS type IV (DTS-HD) can be transmitted with various frame repetition
* periods; longer repetition periods allow for longer packets and therefore
* higher bitrate. Longer repetition periods mean that the constant bitrate of
* the outputted IEC 61937 stream is higher.
* The repetition period is measured in IEC 60958 frames (4 bytes).
*/
static int spdif_dts4_subtype(int period)
{
switch (period) {
case 512: return 0x0;
case 1024: return 0x1;
case 2048: return 0x2;
case 4096: return 0x3;
case 8192: return 0x4;
case 16384: return 0x5;
}
return -1;
}
static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size,
int sample_rate, int blocks)
{
IEC61937Context *ctx = s->priv_data;
static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe };
int pkt_size = pkt->size;
int period;
int subtype;
if (!core_size) {
av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n");
return AVERROR(EINVAL);
}
if (!sample_rate) {
av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n");
return AVERROR_INVALIDDATA;
}
period = ctx->dtshd_rate * (blocks << 5) / sample_rate;
subtype = spdif_dts4_subtype(period);
if (subtype < 0) {
av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an "
"impossible repetition period of %d for the current DTS stream"
" (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period,
blocks << 5, sample_rate);
return AVERROR(EINVAL);
}
/* set pkt_offset and DTS IV subtype according to the requested output
* rate */
ctx->pkt_offset = period * 4;
ctx->data_type = IEC61937_DTSHD | subtype << 8;
/* If the bitrate is too high for transmitting at the selected
* repetition period setting, strip DTS-HD until a good amount
* of consecutive non-overflowing HD frames have been observed.
* This generally only happens if the caller is cramming a Master
* Audio stream into 192kHz IEC 60958 (which may or may not fit). */
if (sizeof(dtshd_start_code) + 2 + pkt_size
> ctx->pkt_offset - BURST_HEADER_SIZE && core_size) {
if (!ctx->dtshd_skip)
av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, "
"temporarily sending core only\n");
if (ctx->dtshd_fallback > 0)
ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5);
else
/* skip permanently (dtshd_fallback == -1) or just once
* (dtshd_fallback == 0) */
ctx->dtshd_skip = 1;
}
if (ctx->dtshd_skip && core_size) {
pkt_size = core_size;
if (ctx->dtshd_fallback >= 0)
--ctx->dtshd_skip;
}
ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size;
/* Align so that (length_code & 0xf) == 0x8. This is reportedly needed
* with some receivers, but the exact requirement is unconfirmed. */
ctx->length_code = FFALIGN(ctx->out_bytes + 0x8, 0x10) - 0x8;
av_fast_malloc(&ctx->hd_buf, &ctx->hd_buf_size, ctx->out_bytes);
if (!ctx->hd_buf)
return AVERROR(ENOMEM);
ctx->out_buf = ctx->hd_buf;
memcpy(ctx->hd_buf, dtshd_start_code, sizeof(dtshd_start_code));
AV_WB16(ctx->hd_buf + sizeof(dtshd_start_code), pkt_size);
memcpy(ctx->hd_buf + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size);
return 0;
}
static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
uint32_t syncword_dts = AV_RB32(pkt->data);
int blocks;
int sample_rate = 0;
int core_size = 0;
if (pkt->size < 9)
return AVERROR_INVALIDDATA;
switch (syncword_dts) {
case DCA_MARKER_RAW_BE:
blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1;
sample_rate = avpriv_dca_sample_rates[(pkt->data[8] >> 2) & 0x0f];
break;
case DCA_MARKER_RAW_LE:
blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
ctx->extra_bswap = 1;
break;
case DCA_MARKER_14B_BE:
blocks =
(((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
break;
case DCA_MARKER_14B_LE:
blocks =
(((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
ctx->extra_bswap = 1;
break;
case DCA_HD_MARKER:
/* We only handle HD frames that are paired with core. However,
sometimes DTS-HD streams with core have a stray HD frame without
core in the beginning of the stream. */
av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n");
return AVERROR_INVALIDDATA;
default:
av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
return AVERROR_INVALIDDATA;
}
blocks++;
if (ctx->dtshd_rate)
/* DTS type IV output requested */
return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks);
switch (blocks) {
case 512 >> 5: ctx->data_type = IEC61937_DTS1; break;
case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break;
case 2048 >> 5: ctx->data_type = IEC61937_DTS3; break;
default:
av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
blocks << 5);
return AVERROR(ENOSYS);
}
/* discard extraneous data by default */
if (core_size && core_size < pkt->size) {
ctx->out_bytes = core_size;
ctx->length_code = core_size << 3;
}
ctx->pkt_offset = blocks << 7;
if (ctx->out_bytes == ctx->pkt_offset) {
/* The DTS stream fits exactly into the output stream, so skip the
* preamble as it would not fit in there. This is the case for dts
* discs and dts-in-wav. */
ctx->use_preamble = 0;
} else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) {
avpriv_request_sample(s, "Unrecognized large DTS frame");
/* This will fail with a "bitrate too high" in the caller */
}
return 0;
}
static const enum IEC61937DataType mpeg_data_type[2][3] = {
// LAYER1 LAYER2 LAYER3
{ IEC61937_MPEG2_LAYER1_LSF, IEC61937_MPEG2_LAYER2_LSF, IEC61937_MPEG2_LAYER3_LSF },//MPEG2 LSF
{ IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, //MPEG1
};
static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
int version = (pkt->data[1] >> 3) & 3;
int layer = 3 - ((pkt->data[1] >> 1) & 3);
int extension = pkt->data[2] & 1;
if (layer == 3 || version == 1) {
av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
return AVERROR_INVALIDDATA;
}
av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
if (version == 2 && extension) {
ctx->data_type = IEC61937_MPEG2_EXT;
ctx->pkt_offset = 4608;
} else {
ctx->data_type = mpeg_data_type [version & 1][layer];
ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];
}
// TODO Data type dependent info (normal/karaoke, dynamic range control)
return 0;
}
static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
AACADTSHeaderInfo hdr;
GetBitContext gbc;
int ret;
init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
ret = avpriv_aac_parse_header(&gbc, &hdr);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
return AVERROR_INVALIDDATA;
}
ctx->pkt_offset = hdr.samples << 2;
switch (hdr.num_aac_frames) {
case 1:
ctx->data_type = IEC61937_MPEG2_AAC;
break;
case 2:
ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048;
break;
case 4:
ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096;
break;
default:
av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
hdr.samples);
return AVERROR(EINVAL);
}
//TODO Data type dependent info (LC profile/SBR)
return 0;
}
/*
* It seems Dolby TrueHD frames have to be encapsulated in MAT frames before
* they can be encapsulated in IEC 61937.
* Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them
* to achieve constant rate.
* The actual format of a MAT frame is unknown, but the below seems to work.
* However, it seems it is not actually necessary for the 24 TrueHD frames to
* be in an exact alignment with the MAT frame.
*/
#define MAT_FRAME_SIZE 61424
#define TRUEHD_FRAME_OFFSET 2560
#define MAT_MIDDLE_CODE_OFFSET -4
static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
int mat_code_length = 0;
static const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 };
if (!ctx->hd_buf_count) {
static const char mat_start_code[20] = { 0x07, 0x9E, 0x00, 0x03, 0x84, 0x01, 0x01, 0x01, 0x80, 0x00, 0x56, 0xA5, 0x3B, 0xF4, 0x81, 0x83, 0x49, 0x80, 0x77, 0xE0 };
mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;
memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code));
} else if (ctx->hd_buf_count == 12) {
static const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 };
mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;
memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET],
mat_middle_code, sizeof(mat_middle_code));
}
if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) {
/* if such frames exist, we'd need some more complex logic to
* distribute the TrueHD frames in the MAT frame */
avpriv_request_sample(s, "Too large TrueHD frame of %d bytes",
pkt->size);
return AVERROR_PATCHWELCOME;
}
memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length],
pkt->data, pkt->size);
memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],
0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);
if (++ctx->hd_buf_count < 24){
ctx->pkt_offset = 0;
return 0;
}
memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code));
ctx->hd_buf_count = 0;
ctx->data_type = IEC61937_TRUEHD;
ctx->pkt_offset = 61440;
ctx->out_buf = ctx->hd_buf;
ctx->out_bytes = MAT_FRAME_SIZE;
ctx->length_code = MAT_FRAME_SIZE;
return 0;
}
static int spdif_write_header(AVFormatContext *s)
{
IEC61937Context *ctx = s->priv_data;
switch (s->streams[0]->codec->codec_id) {
case AV_CODEC_ID_AC3:
ctx->header_info = spdif_header_ac3;
break;
case AV_CODEC_ID_EAC3:
ctx->header_info = spdif_header_eac3;
break;
case AV_CODEC_ID_MP1:
case AV_CODEC_ID_MP2:
case AV_CODEC_ID_MP3:
ctx->header_info = spdif_header_mpeg;
break;
case AV_CODEC_ID_DTS:
ctx->header_info = spdif_header_dts;
break;
case AV_CODEC_ID_AAC:
ctx->header_info = spdif_header_aac;
break;
case AV_CODEC_ID_TRUEHD:
ctx->header_info = spdif_header_truehd;
ctx->hd_buf = av_malloc(MAT_FRAME_SIZE);
if (!ctx->hd_buf)
return AVERROR(ENOMEM);
break;
default:
av_log(s, AV_LOG_ERROR, "codec not supported\n");
return AVERROR_PATCHWELCOME;
}
return 0;
}
static int spdif_write_trailer(AVFormatContext *s)
{
IEC61937Context *ctx = s->priv_data;
av_freep(&ctx->buffer);
av_freep(&ctx->hd_buf);
return 0;
}
static av_always_inline void spdif_put_16(IEC61937Context *ctx,
AVIOContext *pb, unsigned int val)
{
if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)
avio_wb16(pb, val);
else
avio_wl16(pb, val);
}
static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
IEC61937Context *ctx = s->priv_data;
int ret, padding;
ctx->out_buf = pkt->data;
ctx->out_bytes = pkt->size;
ctx->length_code = FFALIGN(pkt->size, 2) << 3;
ctx->use_preamble = 1;
ctx->extra_bswap = 0;
ret = ctx->header_info(s, pkt);
if (ret < 0)
return ret;
if (!ctx->pkt_offset)
return 0;
padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1;
if (padding < 0) {
av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
return AVERROR(EINVAL);
}
if (ctx->use_preamble) {
spdif_put_16(ctx, s->pb, SYNCWORD1); //Pa
spdif_put_16(ctx, s->pb, SYNCWORD2); //Pb
spdif_put_16(ctx, s->pb, ctx->data_type); //Pc
spdif_put_16(ctx, s->pb, ctx->length_code);//Pd
}
if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) {
avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1);
} else {
av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + FF_INPUT_BUFFER_PADDING_SIZE);
if (!ctx->buffer)
return AVERROR(ENOMEM);
ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1);
avio_write(s->pb, ctx->buffer, ctx->out_bytes & ~1);
}
/* a final lone byte has to be MSB aligned */
if (ctx->out_bytes & 1)
spdif_put_16(ctx, s->pb, ctx->out_buf[ctx->out_bytes - 1] << 8);
ffio_fill(s->pb, 0, padding);
av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
ctx->data_type, ctx->out_bytes, ctx->pkt_offset);
return 0;
}
AVOutputFormat ff_spdif_muxer = {
.name = "spdif",
.long_name = NULL_IF_CONFIG_SMALL("IEC 61937 (used on S/PDIF - IEC958)"),
.extensions = "spdif",
.priv_data_size = sizeof(IEC61937Context),
.audio_codec = AV_CODEC_ID_AC3,
.video_codec = AV_CODEC_ID_NONE,
.write_header = spdif_write_header,
.write_packet = spdif_write_packet,
.write_trailer = spdif_write_trailer,
.flags = AVFMT_NOTIMESTAMPS,
.priv_class = &spdif_class,
};
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