gstreamer/gst/rtmp2/rtmp/rtmpchunkstream.c

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/* GStreamer RTMP Library
* Copyright (C) 2017 Make.TV, Inc. <info@make.tv>
* Contact: Jan Alexander Steffens (heftig) <jsteffens@make.tv>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
* Boston, MA 02110-1335, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "rtmpchunkstream.h"
#include "rtmputils.h"
GST_DEBUG_CATEGORY_STATIC (gst_rtmp_chunk_stream_debug_category);
#define GST_CAT_DEFAULT gst_rtmp_chunk_stream_debug_category
static void
init_debug (void)
{
static volatile gsize done = 0;
if (g_once_init_enter (&done)) {
GST_DEBUG_CATEGORY_INIT (gst_rtmp_chunk_stream_debug_category,
"rtmpchunkstream", 0, "debug category for rtmp chunk streams");
g_once_init_leave (&done, 1);
}
}
enum
{
CHUNK_BYTE_TWOBYTE = 0,
CHUNK_BYTE_THREEBYTE = 1,
CHUNK_BYTE_MASK = 0x3f,
CHUNK_STREAM_MIN_TWOBYTE = 0x40,
CHUNK_STREAM_MIN_THREEBYTE = 0x140,
CHUNK_STREAM_MAX_THREEBYTE = 0x1003f,
};
typedef enum
{
CHUNK_TYPE_0 = 0,
CHUNK_TYPE_1 = 1,
CHUNK_TYPE_2 = 2,
CHUNK_TYPE_3 = 3,
} ChunkType;
static const gsize chunk_header_sizes[4] = { 11, 7, 3, 0 };
struct _GstRtmpChunkStream
{
GstBuffer *buffer;
GstRtmpMeta *meta;
GstMapInfo map; /* Only used for parsing */
guint32 id;
guint32 offset;
guint64 bytes;
};
struct _GstRtmpChunkStreams
{
GArray *array;
};
static inline gboolean
chunk_stream_is_open (GstRtmpChunkStream * cstream)
{
return cstream->map.data != NULL;
}
static void
chunk_stream_take_buffer (GstRtmpChunkStream * cstream, GstBuffer * buffer)
{
GstRtmpMeta *meta = gst_buffer_get_rtmp_meta (buffer);
g_assert (meta);
g_assert (cstream->buffer == NULL);
cstream->buffer = buffer;
cstream->meta = meta;
}
static void
chunk_stream_clear (GstRtmpChunkStream * cstream)
{
if (chunk_stream_is_open (cstream)) {
gst_buffer_unmap (cstream->buffer, &cstream->map);
cstream->map.data = NULL;
}
gst_buffer_replace (&cstream->buffer, NULL);
cstream->meta = NULL;
cstream->offset = 0;
}
static guint32
chunk_stream_next_size (GstRtmpChunkStream * cstream, guint32 chunk_size)
{
guint32 size, offset;
size = cstream->meta->size;
offset = cstream->offset;
g_return_val_if_fail (offset <= size, 0);
return MIN (size - offset, chunk_size);
}
static inline gboolean
needs_ext_ts (GstRtmpMeta * meta)
{
return meta->ts_delta >= 0xffffff;
}
static guint32
dts_to_abs_ts (GstBuffer * buffer)
{
GstClockTime dts = GST_BUFFER_DTS (buffer);
guint32 ret = 0;
if (GST_CLOCK_TIME_IS_VALID (dts)) {
ret = gst_util_uint64_scale_round (dts, 1, GST_MSECOND);
}
GST_TRACE ("Converted DTS %" GST_TIME_FORMAT " into abs TS %"
G_GUINT32_FORMAT " ms", GST_TIME_ARGS (dts), ret);
return ret;
}
static gboolean
dts_diff_to_delta_ts (GstBuffer * old_buffer, GstBuffer * buffer,
guint32 * out_ts)
{
GstClockTime dts = GST_BUFFER_DTS (buffer),
old_dts = GST_BUFFER_DTS (old_buffer);
guint32 abs_ts, old_abs_ts, delta_32 = 0;
if (!GST_CLOCK_TIME_IS_VALID (dts) || !GST_CLOCK_TIME_IS_VALID (old_dts)) {
GST_LOG ("Timestamps not valid; using delta TS 0");
goto out;
}
if (ABS (GST_CLOCK_DIFF (old_dts, dts)) > GST_MSECOND * G_MAXINT32) {
GST_WARNING ("Timestamp delta too large: %" GST_TIME_FORMAT " -> %"
GST_TIME_FORMAT, GST_TIME_ARGS (old_dts), GST_TIME_ARGS (dts));
return FALSE;
}
abs_ts = gst_util_uint64_scale_round (dts, 1, GST_MSECOND);
old_abs_ts = gst_util_uint64_scale_round (old_dts, 1, GST_MSECOND);
/* underflow wraps around */
delta_32 = abs_ts - old_abs_ts;
GST_TRACE ("Converted DTS %" GST_TIME_FORMAT " (%" G_GUINT32_FORMAT
" ms) -> %" GST_TIME_FORMAT " (%" G_GUINT32_FORMAT " ms) into delta TS %"
G_GUINT32_FORMAT " ms", GST_TIME_ARGS (old_dts), old_abs_ts,
GST_TIME_ARGS (dts), abs_ts, delta_32);
out:
*out_ts = delta_32;
return TRUE;
}
static ChunkType
select_chunk_type (GstRtmpChunkStream * cstream, GstBuffer * buffer)
{
GstBuffer *old_buffer = cstream->buffer;
GstRtmpMeta *meta, *old_meta;
g_return_val_if_fail (buffer, -1);
meta = gst_buffer_get_rtmp_meta (buffer);
g_return_val_if_fail (meta, -1);
g_return_val_if_fail (gst_rtmp_message_type_is_valid (meta->type), -1);
meta->size = gst_buffer_get_size (buffer);
meta->cstream = cstream->id;
if (!old_buffer) {
GST_TRACE ("Picking header 0: no previous header");
meta->ts_delta = dts_to_abs_ts (buffer);
return CHUNK_TYPE_0;
}
old_meta = gst_buffer_get_rtmp_meta (old_buffer);
g_return_val_if_fail (old_meta, -1);
if (old_meta->mstream != meta->mstream) {
GST_TRACE ("Picking header 0: stream mismatch; "
"want %" G_GUINT32_FORMAT " got %" G_GUINT32_FORMAT,
old_meta->mstream, meta->mstream);
meta->ts_delta = dts_to_abs_ts (buffer);
return CHUNK_TYPE_0;
}
if (!dts_diff_to_delta_ts (old_buffer, buffer, &meta->ts_delta)) {
GST_TRACE ("Picking header 0: timestamp delta overflow");
meta->ts_delta = dts_to_abs_ts (buffer);
return CHUNK_TYPE_0;
}
/* now at least type 1 */
if (old_meta->type != meta->type) {
GST_TRACE ("Picking header 1: type mismatch; want %d got %d",
old_meta->type, meta->type);
return CHUNK_TYPE_1;
}
if (old_meta->size != meta->size) {
GST_TRACE ("Picking header 1: size mismatch; "
"want %" G_GUINT32_FORMAT " got %" G_GUINT32_FORMAT,
old_meta->size, meta->size);
return CHUNK_TYPE_1;
}
/* now at least type 2 */
if (old_meta->ts_delta != meta->ts_delta) {
GST_TRACE ("Picking header 2: timestamp delta mismatch; "
"want %" G_GUINT32_FORMAT " got %" G_GUINT32_FORMAT,
old_meta->ts_delta, meta->ts_delta);
return CHUNK_TYPE_2;
}
/* now at least type 3 */
GST_TRACE ("Picking header 3");
return CHUNK_TYPE_3;
}
static GstBuffer *
serialize_next (GstRtmpChunkStream * cstream, guint32 chunk_size,
ChunkType type)
{
GstRtmpMeta *meta = cstream->meta;
guint8 small_stream_id;
gsize header_size = chunk_header_sizes[type], offset;
gboolean ext_ts;
GstBuffer *ret;
GstMapInfo map;
GST_TRACE ("Serializing a chunk of type %d, offset %" G_GUINT32_FORMAT,
type, cstream->offset);
if (cstream->id < CHUNK_STREAM_MIN_TWOBYTE) {
small_stream_id = cstream->id;
header_size += 1;
} else if (cstream->id < CHUNK_STREAM_MIN_THREEBYTE) {
small_stream_id = CHUNK_BYTE_TWOBYTE;
header_size += 2;
} else {
small_stream_id = CHUNK_BYTE_THREEBYTE;
header_size += 3;
}
ext_ts = needs_ext_ts (meta);
if (ext_ts) {
header_size += 4;
}
GST_TRACE ("Allocating buffer, header size %" G_GSIZE_FORMAT, header_size);
ret = gst_buffer_new_allocate (NULL, header_size, NULL);
if (!ret) {
GST_ERROR ("Failed to allocate chunk buffer");
return NULL;
}
if (!gst_buffer_map (ret, &map, GST_MAP_WRITE)) {
GST_ERROR ("Failed to map %" GST_PTR_FORMAT, ret);
gst_buffer_unref (ret);
return NULL;
}
/* Chunk Basic Header */
GST_WRITE_UINT8 (map.data, (type << 6) | small_stream_id);
offset = 1;
switch (small_stream_id) {
case CHUNK_BYTE_TWOBYTE:
GST_WRITE_UINT8 (map.data + 1, cstream->id - CHUNK_STREAM_MIN_TWOBYTE);
offset += 1;
break;
case CHUNK_BYTE_THREEBYTE:
GST_WRITE_UINT16_LE (map.data + 1,
cstream->id - CHUNK_STREAM_MIN_TWOBYTE);
offset += 2;
break;
}
switch (type) {
case CHUNK_TYPE_0:
/* SRSLY: "Message stream ID is stored in little-endian format." */
GST_WRITE_UINT32_LE (map.data + offset + 7, meta->mstream);
/* no break */
case CHUNK_TYPE_1:
GST_WRITE_UINT24_BE (map.data + offset + 3, meta->size);
GST_WRITE_UINT8 (map.data + offset + 6, meta->type);
/* no break */
case CHUNK_TYPE_2:
GST_WRITE_UINT24_BE (map.data + offset,
ext_ts ? 0xffffff : meta->ts_delta);
/* no break */
case CHUNK_TYPE_3:
offset += chunk_header_sizes[type];
if (ext_ts) {
GST_WRITE_UINT32_BE (map.data + offset, meta->ts_delta);
offset += 4;
}
}
g_assert (offset == header_size);
GST_MEMDUMP (">>> chunk header", map.data, offset);
gst_buffer_unmap (ret, &map);
GST_BUFFER_OFFSET (ret) = GST_BUFFER_OFFSET_IS_VALID (cstream->buffer) ?
GST_BUFFER_OFFSET (cstream->buffer) + cstream->offset : cstream->bytes;
GST_BUFFER_OFFSET_END (ret) = GST_BUFFER_OFFSET (ret);
if (meta->size > 0) {
guint32 payload_size = chunk_stream_next_size (cstream, chunk_size);
GST_TRACE ("Appending %" G_GUINT32_FORMAT " bytes of payload",
payload_size);
gst_buffer_copy_into (ret, cstream->buffer, GST_BUFFER_COPY_MEMORY,
cstream->offset, payload_size);
GST_BUFFER_OFFSET_END (ret) += payload_size;
cstream->offset += payload_size;
cstream->bytes += payload_size;
} else {
GST_TRACE ("Chunk has no payload");
}
gst_rtmp_buffer_dump (ret, ">>> chunk");
return ret;
}
void
gst_rtmp_chunk_stream_clear (GstRtmpChunkStream * cstream)
{
g_return_if_fail (cstream);
GST_LOG ("Clearing chunk stream %" G_GUINT32_FORMAT, cstream->id);
chunk_stream_clear (cstream);
}
guint32
gst_rtmp_chunk_stream_parse_id (const guint8 * data, gsize size)
{
guint32 ret;
if (size < 1) {
GST_TRACE ("Not enough bytes to read ID");
return 0;
}
ret = GST_READ_UINT8 (data) & CHUNK_BYTE_MASK;
switch (ret) {
case CHUNK_BYTE_TWOBYTE:
if (size < 2) {
GST_TRACE ("Not enough bytes to read two-byte ID");
return 0;
}
ret = GST_READ_UINT8 (data + 1) + CHUNK_STREAM_MIN_TWOBYTE;
break;
case CHUNK_BYTE_THREEBYTE:
if (size < 3) {
GST_TRACE ("Not enough bytes to read three-byte ID");
return 0;
}
ret = GST_READ_UINT16_LE (data + 1) + CHUNK_STREAM_MIN_TWOBYTE;
break;
}
GST_TRACE ("Parsed chunk stream ID %" G_GUINT32_FORMAT, ret);
return ret;
}
guint32
gst_rtmp_chunk_stream_parse_header (GstRtmpChunkStream * cstream,
const guint8 * data, gsize size)
{
GstBuffer *buffer;
GstRtmpMeta *meta;
const guint8 *message_header;
guint32 header_size;
ChunkType type;
gboolean has_abs_timestamp = FALSE;
g_return_val_if_fail (cstream, 0);
g_return_val_if_fail (cstream->id == gst_rtmp_chunk_stream_parse_id (data,
size), 0);
type = GST_READ_UINT8 (data) >> 6;
GST_TRACE ("Parsing chunk stream %" G_GUINT32_FORMAT " header type %d",
cstream->id, type);
switch (GST_READ_UINT8 (data) & CHUNK_BYTE_MASK) {
case CHUNK_BYTE_TWOBYTE:
header_size = 2;
break;
case CHUNK_BYTE_THREEBYTE:
header_size = 3;
break;
default:
header_size = 1;
break;
}
message_header = data + header_size;
header_size += chunk_header_sizes[type];
if (cstream->buffer) {
buffer = cstream->buffer;
meta = cstream->meta;
g_assert (meta->cstream == cstream->id);
} else {
buffer = gst_buffer_new ();
GST_BUFFER_DTS (buffer) = 0;
GST_BUFFER_OFFSET (buffer) = cstream->bytes;
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
meta = gst_buffer_add_rtmp_meta (buffer);
meta->cstream = cstream->id;
chunk_stream_take_buffer (cstream, buffer);
GST_DEBUG ("Starting parse with new %" GST_PTR_FORMAT, buffer);
}
if (size < header_size) {
GST_TRACE ("not enough bytes to read header");
return header_size;
}
switch (type) {
case CHUNK_TYPE_0:
has_abs_timestamp = TRUE;
/* SRSLY: "Message stream ID is stored in little-endian format." */
meta->mstream = GST_READ_UINT32_LE (message_header + 7);
/* no break */
case CHUNK_TYPE_1:
meta->type = GST_READ_UINT8 (message_header + 6);
meta->size = GST_READ_UINT24_BE (message_header + 3);
/* no break */
case CHUNK_TYPE_2:
meta->ts_delta = GST_READ_UINT24_BE (message_header);
/* no break */
case CHUNK_TYPE_3:
if (needs_ext_ts (meta)) {
guint32 timestamp;
if (size < header_size + 4) {
GST_TRACE ("not enough bytes to read extended timestamp");
return header_size + 4;
}
GST_TRACE ("Reading extended timestamp");
timestamp = GST_READ_UINT32_BE (data + header_size);
if (type == 3 && meta->ts_delta != timestamp) {
GST_WARNING ("Type 3 extended timestamp does not match expected"
" timestamp (want %" G_GUINT32_FORMAT " got %" G_GUINT32_FORMAT
"); assuming it's not present", meta->ts_delta, timestamp);
} else {
meta->ts_delta = timestamp;
header_size += 4;
}
}
}
GST_MEMDUMP ("<<< chunk header", data, header_size);
if (!chunk_stream_is_open (cstream)) {
GstClockTime dts = GST_BUFFER_DTS (buffer);
guint32 delta_32, abs_32;
gint64 delta_64;
if (has_abs_timestamp) {
abs_32 = meta->ts_delta;
delta_32 = abs_32 - dts / GST_MSECOND;
} else {
delta_32 = meta->ts_delta;
abs_32 = delta_32 + dts / GST_MSECOND;
}
GST_TRACE ("Timestamp delta is %" G_GUINT32_FORMAT " (absolute %"
G_GUINT32_FORMAT ")", delta_32, abs_32);
/* emulate signed overflow */
delta_64 = delta_32;
if (delta_64 > G_MAXINT32) {
delta_64 -= G_MAXUINT32;
delta_64 -= 1;
}
delta_64 *= GST_MSECOND;
if (G_LIKELY (delta_64 >= 0)) {
/* Normal advancement */
} else if (G_LIKELY ((guint64) (-delta_64) <= dts)) {
/* In-bounds regression */
GST_WARNING ("Timestamp regression: %" GST_STIME_FORMAT,
GST_STIME_ARGS (delta_64));
} else {
/* Out-of-bounds regression */
GST_WARNING ("Timestamp regression: %" GST_STIME_FORMAT ", offsetting",
GST_STIME_ARGS (delta_64));
delta_64 = delta_32 * GST_MSECOND;
}
GST_BUFFER_DTS (buffer) += delta_64;
GST_TRACE ("Adjusted buffer DTS (%" GST_TIME_FORMAT ") by %"
GST_STIME_FORMAT " to %" GST_TIME_FORMAT, GST_TIME_ARGS (dts),
GST_STIME_ARGS (delta_64), GST_TIME_ARGS (GST_BUFFER_DTS (buffer)));
} else {
GST_TRACE ("Message payload already started; not touching timestamp");
}
return header_size;
}
guint32
gst_rtmp_chunk_stream_parse_payload (GstRtmpChunkStream * cstream,
guint32 chunk_size, guint8 ** data)
{
GstMemory *mem;
g_return_val_if_fail (cstream, 0);
g_return_val_if_fail (cstream->buffer, 0);
if (!chunk_stream_is_open (cstream)) {
guint32 size = cstream->meta->size;
GST_TRACE ("Allocating buffer, payload size %" G_GUINT32_FORMAT, size);
mem = gst_allocator_alloc (NULL, size, 0);
if (!mem) {
GST_ERROR ("Failed to allocate buffer for payload size %"
G_GUINT32_FORMAT, size);
return 0;
}
gst_buffer_append_memory (cstream->buffer, mem);
gst_buffer_map (cstream->buffer, &cstream->map, GST_MAP_WRITE);
}
g_return_val_if_fail (cstream->map.size == cstream->meta->size, 0);
if (data) {
*data = cstream->map.data + cstream->offset;
}
return chunk_stream_next_size (cstream, chunk_size);
}
guint32
gst_rtmp_chunk_stream_wrote_payload (GstRtmpChunkStream * cstream,
guint32 chunk_size)
{
guint32 size;
g_return_val_if_fail (cstream, FALSE);
g_return_val_if_fail (chunk_stream_is_open (cstream), FALSE);
size = chunk_stream_next_size (cstream, chunk_size);
cstream->offset += size;
cstream->bytes += size;
return chunk_stream_next_size (cstream, chunk_size);
}
GstBuffer *
gst_rtmp_chunk_stream_parse_finish (GstRtmpChunkStream * cstream)
{
GstBuffer *buffer, *empty;
g_return_val_if_fail (cstream, NULL);
g_return_val_if_fail (cstream->buffer, NULL);
buffer = gst_buffer_ref (cstream->buffer);
GST_BUFFER_OFFSET_END (buffer) = cstream->bytes;
gst_rtmp_buffer_dump (buffer, "<<< message");
chunk_stream_clear (cstream);
empty = gst_buffer_new ();
if (!gst_buffer_copy_into (empty, buffer, GST_BUFFER_COPY_META, 0, 0)) {
GST_ERROR ("copy_into failed");
return NULL;
}
GST_BUFFER_DTS (empty) = GST_BUFFER_DTS (buffer);
GST_BUFFER_OFFSET (empty) = GST_BUFFER_OFFSET_END (buffer);
chunk_stream_take_buffer (cstream, empty);
return buffer;
}
GstBuffer *
gst_rtmp_chunk_stream_serialize_start (GstRtmpChunkStream * cstream,
GstBuffer * buffer, guint32 chunk_size)
{
ChunkType type;
g_return_val_if_fail (cstream, NULL);
g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
type = select_chunk_type (cstream, buffer);
g_return_val_if_fail (type >= 0, NULL);
GST_TRACE ("Starting serialization of message %" GST_PTR_FORMAT
" into stream %" G_GUINT32_FORMAT, buffer, cstream->id);
gst_rtmp_buffer_dump (buffer, ">>> message");
chunk_stream_clear (cstream);
chunk_stream_take_buffer (cstream, buffer);
return serialize_next (cstream, chunk_size, type);
}
GstBuffer *
gst_rtmp_chunk_stream_serialize_next (GstRtmpChunkStream * cstream,
guint32 chunk_size)
{
g_return_val_if_fail (cstream, NULL);
g_return_val_if_fail (cstream->buffer, NULL);
if (chunk_stream_next_size (cstream, chunk_size) == 0) {
GST_TRACE ("Message serialization finished");
return NULL;
}
GST_TRACE ("Continuing serialization of message %" GST_PTR_FORMAT
" into stream %" G_GUINT32_FORMAT, cstream->buffer, cstream->id);
return serialize_next (cstream, chunk_size, CHUNK_TYPE_3);
}
GstRtmpChunkStreams *
gst_rtmp_chunk_streams_new (void)
{
GstRtmpChunkStreams *cstreams;
init_debug ();
cstreams = g_slice_new (GstRtmpChunkStreams);
cstreams->array = g_array_new (FALSE, TRUE, sizeof (GstRtmpChunkStream));
g_array_set_clear_func (cstreams->array,
(GDestroyNotify) gst_rtmp_chunk_stream_clear);
return cstreams;
}
void
gst_rtmp_chunk_streams_free (gpointer ptr)
{
GstRtmpChunkStreams *cstreams = ptr;
g_clear_pointer (&cstreams->array, g_array_unref);
g_slice_free (GstRtmpChunkStreams, cstreams);
}
GstRtmpChunkStream *
gst_rtmp_chunk_streams_get (GstRtmpChunkStreams * cstreams, guint32 id)
{
GArray *array;
GstRtmpChunkStream *entry;
guint i;
g_return_val_if_fail (cstreams, NULL);
g_return_val_if_fail (id > CHUNK_BYTE_THREEBYTE, NULL);
g_return_val_if_fail (id <= CHUNK_STREAM_MAX_THREEBYTE, NULL);
array = cstreams->array;
for (i = 0; i < array->len; i++) {
entry = &g_array_index (array, GstRtmpChunkStream, i);
if (entry->id == id) {
GST_TRACE ("Obtaining chunk stream %" G_GUINT32_FORMAT, id);
return entry;
}
}
GST_DEBUG ("Allocating chunk stream %" G_GUINT32_FORMAT, id);
g_array_set_size (array, i + 1);
entry = &g_array_index (array, GstRtmpChunkStream, i);
entry->id = id;
return entry;
}