[FFmpeg-devel] [PATCH] spdifenc: IEC 61937 encapsulation of DTS-HD for HDMI
Anssi Hannula
anssi.hannula
Fri Feb 4 15:44:57 CET 2011
On 29.01.2011 03:36, Anssi Hannula wrote:
> ---
>
> Here's this patch again, modified for Justin's comments and rebased to
> master (and tested it is still working).
Ping.
[...]
> Changelog | 2 +-
> libavformat/spdifenc.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
> libavformat/version.h | 2 +-
> 3 files changed, 150 insertions(+), 2 deletions(-)
>
> diff --git a/Changelog b/Changelog
> index 8b7efb6..c4e565a 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -55,7 +55,7 @@ version <next>:
> - Win64 support for optimized asm functions
> - MJPEG/AVI1 to JPEG/JFIF bitstream filter
> - ASS subtitle encoder and decoder
> -- IEC 61937 encapsulation for E-AC3 and TrueHD (for HDMI passthrough)
> +- IEC 61937 encapsulation for E-AC3, TrueHD, DTS-HD (for HDMI passthrough)
> - overlay filter added
> - rename aspect filter to setdar, and pixelaspect to setsar
> - IEC 61937 demuxer
> diff --git a/libavformat/spdifenc.c b/libavformat/spdifenc.c
> index 3eea31e..3c6fd73 100644
> --- a/libavformat/spdifenc.c
> +++ b/libavformat/spdifenc.c
> @@ -48,9 +48,12 @@
> #include "spdif.h"
> #include "libavcodec/ac3.h"
> #include "libavcodec/dca.h"
> +#include "libavcodec/dcadata.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
> @@ -68,11 +71,24 @@ typedef struct IEC61937Context {
> 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;
> +
> /// 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[] = {
> +{ "dtshd_rate", "mux complete DTS frames in HD mode at the specified IEC958 rate (in Hz, default 0=disabled)", offsetof(IEC61937Context, dtshd_rate), FF_OPT_TYPE_INT, 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), FF_OPT_TYPE_INT, 60, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
> +{ NULL },
> +};
> +
> +static const AVClass class = { "spdif", av_default_item_name, options, LIBAVUTIL_VERSION_INT };
>
> static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
> {
> @@ -115,15 +131,125 @@ static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
> 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).
> + */
> +enum {
> + DTS4_REP_PER_512 = 0x0,
> + DTS4_REP_PER_1024 = 0x1,
> + DTS4_REP_PER_2048 = 0x2,
> + DTS4_REP_PER_4096 = 0x3,
> + DTS4_REP_PER_8192 = 0x4,
> + DTS4_REP_PER_16384 = 0x5,
> +};
> +
> +static int spdif_dts4_subtype(int period)
> +{
> + switch (period) {
> + case 512: return DTS4_REP_PER_512;
> + case 1024: return DTS4_REP_PER_1024;
> + case 2048: return DTS4_REP_PER_2048;
> + case 4096: return DTS4_REP_PER_4096;
> + case 8192: return DTS4_REP_PER_8192;
> + case 16384: return DTS4_REP_PER_16384;
> + }
> + 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 (-1) or just once (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;
> + ctx->length_code = ctx->out_bytes;
> +
> + ctx->hd_buf = av_fast_realloc(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 = dca_sample_rates[(pkt->data[8] >> 2) & 0x0f];
> break;
> case DCA_MARKER_RAW_LE:
> blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
> @@ -138,11 +264,22 @@ static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
> (((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;
> @@ -152,6 +289,13 @@ static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
> 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) {
> @@ -159,6 +303,9 @@ static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
> * 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) {
> + av_log_ask_for_sample(s, "Unrecognized large DTS frame.");
> + /* This will fail with a "bitrate too high" in the caller */
> }
>
> return 0;
> @@ -393,4 +540,5 @@ AVOutputFormat ff_spdif_muxer = {
> spdif_write_header,
> spdif_write_packet,
> spdif_write_trailer,
> + .priv_class = &class,
> };
> diff --git a/libavformat/version.h b/libavformat/version.h
> index 9a902aa..807bcb3 100644
> --- a/libavformat/version.h
> +++ b/libavformat/version.h
> @@ -25,7 +25,7 @@
>
> #define LIBAVFORMAT_VERSION_MAJOR 52
> #define LIBAVFORMAT_VERSION_MINOR 94
> -#define LIBAVFORMAT_VERSION_MICRO 0
> +#define LIBAVFORMAT_VERSION_MICRO 1
>
> #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
> LIBAVFORMAT_VERSION_MINOR, \
--
Anssi Hannula
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