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Add Brotli compression and improve compression code
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@cyanreg
cyanreg committed Dec 8, 2023
1 parent 67c132b commit a918281
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42 changes: 30 additions & 12 deletions draft-avtransport-spec.bs
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Original file line number Diff line number Diff line change
Expand Up @@ -847,18 +847,21 @@ in the following manner:

: <dfn>STREAM_HEARING_IMPAIRED</dfn> = 0x200
:: Stream is intended for hearing impaired audiences.
Note: If [=related_stream_id=] is not equal to [=stream_id=], both should be mixed in.

Note: If [=related_stream_id=] is not equal to [=stream_id=], both should be mixed in.

: <dfn>STREAM_VISUALLY_IMPAIRED</dfn> = <i>0x400</i>
:: Stream is intended for visually impaired audiences.
Note: If [=related_stream_id=] is not equal to [=stream_id=], both should be mixed in.

Note: If [=related_stream_id=] is not equal to [=stream_id=], both should be mixed in.

: <dfn>STREAM_NO_DIALOGUE</dfn> = <i>0x800</i>
:: Stream contains music and sound effects without voice.

: <dfn>STREAM_NON_DIEGETIC</dfn> = <i>0x1000</i>
:: Stream contains non-diegetic audio.
Note: If [=related_stream_id=] is not equal to [=stream_id=], both should be mixed in.

Note: If [=related_stream_id=] is not equal to [=stream_id=], both should be mixed in.

: <dfn>STREAM_DESCRIPTIONS</dfn> = <i>0x2000</i>
:: Stream contains textual or spoken descriptions to the stream signalled in [=related_stream_id=].
Expand Down Expand Up @@ -1313,6 +1316,17 @@ the [[#codec-encapsulation]] addenda.
:: Packet data is uncompressed
: <dfn>DATA_COMPRESSION_ZSTD</dfn> = <i>0x1</i>
:: Packet data is compressed with Zstandard, defined in IETF [[RFC8878]].

Note: Zstandard is a general purpose format, suitable for images,
audio, and binary data such as ICC or CUBE packets. Therefore,
it should be the preferred format for such payloads.

: <dfn>DATA_COMPRESSION_BROTLI</dfn> = <i>0x2</i>
:: Packet data is compressed with Zstandard, defined in IETF [[RFC7932]].

Note: Brotli is more optimized for <b>text</b> rather than generic data,
and should be the preferred format for subtitles. Presently, it is
also more supported on the web.
</div>

Any undefined values are hereby reserved and must not be present in a compliant
Expand Down Expand Up @@ -1394,6 +1408,7 @@ FEC grouped streams MUST be registered first via a special packet:
<td></td>
<td>
Indicates the ID for this FEC grouping.</br>

Note: Must not overlap with [=stream_id=].
</td>
</tr>
Expand Down Expand Up @@ -2061,6 +2076,7 @@ The following structure MUST be followed:
<td></td>
<td>
The stream ID for which to make the font available.

Note: may be set to ''0xffff'' to make the font available for all streams.
</td>
</tr>
Expand Down Expand Up @@ -2415,7 +2431,9 @@ The [=colorspace=] field must be interpreted in the following way:
:: Video contains [[CIE1931]] XYZ color data.
: <dfn>CSP_XYB</dfn> = <i>0x6</i>
:: Video contains XYB color data, as defined by [[ISO18181]].
Note: [matrix] must be equal to ''0xFF'' and the [=custom_matrix=] must be a valid matrix to transform XYB into RGB.

Note: [matrix] must be equal to ''0xFF'' and the [=custom_matrix=] must be a valid matrix to transform XYB into RGB.

: <dfn>CSP_ICTCP</dfn> = <i>0x5</i>
:: Video contains [[BT2100]] ICtCp color data.
: <dfn>CSP_BAYER_BGGR</dfn> = <i>0x6</i>
Expand All @@ -2438,10 +2456,10 @@ The [=colorspace=] field must be interpreted in the following way:
:: Video sample values contains the limited range of the [=bit_depth=].

Note: this describes the <i>cannonical</i> limited range representation:
<code>(219 * E + 16) * 2<sup>([=bit_depth=]-8)</sup></code>,
where <code>E</code>, the input range, is ''0.0'' to ''1.0'' for <i>luma</i> planes and
''-0.5'' to ''0.5'' for <i>chroma</i> planes. This means, for 8-bits, the luma
range is 16-235 and the chroma range is 16-240.
<code>(219 * E + 16) * 2<sup>([=bit_depth=]-8)</sup></code>,
where <code>E</code>, the input range, is ''0.0'' to ''1.0'' for <i>luma</i> planes and
''-0.5'' to ''0.5'' for <i>chroma</i> planes. This means, for 8-bits, the luma
range is 16-235 and the chroma range is 16-240.
</div>


Expand All @@ -2466,7 +2484,7 @@ to interpret the value of [=field_id=] in stream data packet headers.
: <dfn>ILACE_PROG</dfn> = <i>0x0</i>
:: Video contains progressive data, or interlacing does not apply.

Note: in this mode, the [=field_id=] bit is free to use by users. Implementations must ignore it, and preserve it.
Note: in this mode, the [=field_id=] bit is free to use by users. Implementations must ignore it, and preserve it.

: <dfn>ILACE_TFF</dfn> = <i>0x1</i>
:: Video is interlaced. One [[#stream-data-packets]] packet per <i>field</i>. If the data packet's [=field_id=] bit is <b>unset</b>, indicates the field contained is the <b>top</b> field, otherwise it's the <i>bottom</i> field.
Expand All @@ -2491,17 +2509,17 @@ the setting used, if the codec supports this.
: <dfn>CHROMA_POS_LEFT</dfn> = <i>0x1</i>
:: Chroma position is between 2 luma samples on different lines.

Note: This is the default chroma position for MPEG-2, H.263 with {{CHROMA_422}}, and H.264 with {{CHROMA_420}}.
Note: This is the default chroma position for MPEG-2, H.263 with {{CHROMA_422}}, and H.264 with {{CHROMA_420}}.

: <dfn>CHROMA_POS_CENTER</dfn> = <i>0x2</i>
:: Chroma position is in the middle between all neighbouring luma samples on 2 lines.

Note: This is the default chroma position for JPEG with {{CHROMA_420}}, and H.263 with {{CHROMA_420}}.
Note: This is the default chroma position for JPEG with {{CHROMA_420}}, and H.263 with {{CHROMA_420}}.

: <dfn>CHROMA_POS_TOPLEFT</dfn> = <i>0x3</i>
:: Chroma position coincides with top left's luma sample position.

Note: This is the default chroma position for MPEG-2 with {{CHROMA_422}}.
Note: This is the default chroma position for MPEG-2 with {{CHROMA_422}}.

: <dfn>CHROMA_POS_TOP</dfn> = <i>0x4</i>
:: Chroma position is between 2 luma samples on the same top line.
Expand Down
57 changes: 55 additions & 2 deletions libavtransport/output_packet.c
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Original file line number Diff line number Diff line change
Expand Up @@ -28,10 +28,16 @@

#include "output_packet.h"

#include "../config.h"

#ifdef CONFIG_HAVE_LIBZSTD
#include <zstd.h>
#endif

#ifdef CONFIG_HAVE_LIBBROTLI
#include <brotli/encode.h>
#endif

static inline int avt_send_pkt(union AVTPacketData pkt)
{

Expand All @@ -49,13 +55,21 @@ static inline int avt_interleave_start(AVTOutput *out, AVTStream *st,
return 0;
}

#ifdef CONFIG_HAVE_LIBBROTLI
static void avt_brotli_data_free(void *opaque, void *base_data)
{
BrotliEncoderState *brotli_ctx = opaque;
BrotliEncoderDestroyInstance(brotli_ctx);
}
#endif

static inline int avt_payload_compress(AVTOutput *out,
AVTBuffer **data, enum AVTPktDescriptors desc,
enum AVTDataCompression *data_compression)
{
int err = 0;

int lvl = 0;
int lvl = -1;
enum AVTDataCompression method = AVT_DATA_COMPRESSION_NONE;

switch (method) {
Expand All @@ -71,7 +85,8 @@ static inline int avt_payload_compress(AVTOutput *out,
if (!dst)
return AVT_ERROR(ENOMEM);

size_t dst_len = ZSTD_compressCCtx(out->zstd_ctx, dst, dst_size, src, src_len, lvl);
size_t dst_len = ZSTD_compressCCtx(out->zstd_ctx, dst, dst_size, src, src_len,
lvl < 0 ? ZSTD_CLEVEL_DEFAULT : lvl);
if (!dst_len) {
avt_log(out, AVT_LOG_ERROR, "Error while compressing with ZSTD!\n");
err = AVT_ERROR(EINVAL);
Expand All @@ -90,6 +105,44 @@ static inline int avt_payload_compress(AVTOutput *out,
#else
avt_log(out, AVT_LOG_ERROR, "ZSTD compression not enabled during build!\n");
err = AVT_ERROR(EINVAL);
#endif
break;
}
case AVT_DATA_COMPRESSION_BROTLI: {
#ifdef CONFIG_HAVE_LIBBROTLI
size_t src_len;
uint8_t *src = avt_buffer_get_data(*data, &src_len);

size_t dst_size = BrotliEncoderMaxCompressedSize(src_len);

/* TODO: use a buffer pool */
uint8_t *dst = malloc(dst_size);
if (!dst)
return AVT_ERROR(ENOMEM);

/* Brotli has a braindead advanced API that
* makes it really hard to use pooling. Since Brotli is mostly
* used by text, meh, good enough for now. */
if (!BrotliEncoderCompress(lvl < 0 ? BROTLI_DEFAULT_QUALITY : lvl,
BROTLI_DEFAULT_WINDOW, BROTLI_DEFAULT_MODE,
src_len, src, &dst_size, dst)) {
avt_log(out, AVT_LOG_ERROR, "Error while compressing with Brotli!\n");
err = AVT_ERROR(EINVAL);
free(dst);
break;
}

AVTBuffer *tmp = avt_buffer_create(dst, dst_size, NULL, avt_buffer_default_free);
if (!tmp) {
free(dst);
err = AVT_ERROR(ENOMEM);
break;
}

*data = tmp;
#else
avt_log(out, AVT_LOG_ERROR, "Brotli compression not enabled during build!\n");
err = AVT_ERROR(EINVAL);
#endif
break;
}
Expand Down
3 changes: 3 additions & 0 deletions meson.build
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Original file line number Diff line number Diff line change
Expand Up @@ -87,12 +87,14 @@ endif
threads_dep = dependency('threads', required: true)
uring_dep = dependency('liburing', required: false)
zstd_dep = dependency('libzstd', required: false)
brotli_dep = dependency('libzstd', required: false)
lib_deps = [
cc.find_library('m', required: true),
threads_dep,

uring_dep,
zstd_dep,
brotli_dep,
]

# Configure file
Expand All @@ -111,6 +113,7 @@ conf.set('CONFIG_OUTPUT', get_option('output').auto())

conf.set('CONFIG_HAVE_LIBURING', uring_dep.found())
conf.set('CONFIG_HAVE_LIBZSTD', zstd_dep.found())
conf.set('CONFIG_HAVE_LIBBROTLI', brotli_dep.found())

if get_option('assert') > -1
conf.set('CONFIG_ASSERT_LEVEL', get_option('assert'))
Expand Down

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