tsmux: Simplify tsmux_section_write_packet

- Don't try to make the parameters match `GHFunc`. Use a dedicated
  callback for `g_hash_table_foreach`.
- Don't try to be clever with buffer memories. We're allocating a full
  packet anyway, might as well memcpy and save on a lot of complexity.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5516>
This commit is contained in:
Jan Alexander Steffens (heftig) 2023-10-17 00:57:56 +02:00 committed by GStreamer Marge Bot
parent c205086f2b
commit 77429e4096

View file

@ -1147,132 +1147,80 @@ tsmux_write_ts_header (TsMux * mux, guint8 * buf, TsMuxPacketInfo * pi,
return TRUE;
}
/* The unused_arg is needed for g_hash_table_foreach() */
static gboolean
tsmux_section_write_packet (gpointer unused_arg,
TsMuxSection * section, TsMux * mux)
tsmux_section_write_packet (TsMux * mux, TsMuxSection * section)
{
GstBuffer *section_buffer;
GstBuffer *packet_buffer = NULL;
GstMemory *mem;
guint8 *packet;
guint8 *data;
gsize data_size = 0;
gsize payload_written;
guint len = 0, offset = 0, payload_len = 0;
guint extra_alloc_bytes = 0;
gsize data_size;
guint payload_written = 0;
gboolean ret = FALSE;
g_return_val_if_fail (section != NULL, FALSE);
g_return_val_if_fail (mux != NULL, FALSE);
/* Mark the start of new PES unit */
section->pi.packet_start_unit_indicator = TRUE;
data = gst_mpegts_section_packetize (section->section, &data_size);
if (!data) {
TS_DEBUG ("Could not packetize section");
GST_WARNING ("Could not packetize section");
return FALSE;
}
/* Mark the start of new PES unit */
section->pi.packet_start_unit_indicator = TRUE;
/* Mark payload data size */
section->pi.stream_avail = data_size;
payload_written = 0;
/* Wrap section data in a buffer without free function.
The data will be freed when the GstMpegtsSection is destroyed. */
section_buffer = gst_buffer_new_wrapped_full (GST_MEMORY_FLAG_READONLY,
data, data_size, 0, data_size, NULL, NULL);
TS_DEBUG ("Section buffer with size %" G_GSIZE_FORMAT " created",
gst_buffer_get_size (section_buffer));
while (section->pi.stream_avail > 0) {
GstBuffer *buf;
GstMapInfo map;
guint len, offset;
packet = g_malloc (TSMUX_PACKET_LENGTH);
if (!tsmux_get_buffer (mux, &buf))
goto done;
if (!gst_buffer_map (buf, &map, GST_MAP_WRITE)) {
gst_buffer_unref (buf);
goto done;
}
if (section->pi.packet_start_unit_indicator) {
/* Wee need room for a pointer byte */
section->pi.stream_avail++;
if (!tsmux_write_ts_header (mux, packet, &section->pi,
section->pi.stream_avail, &len, &offset))
goto fail;
/* We need room for a pointer byte */
if (!tsmux_write_ts_header (mux, map.data, &section->pi,
section->pi.stream_avail + 1, &len, &offset)) {
gst_buffer_unmap (buf, &map);
gst_buffer_unref (buf);
goto done;
}
/* Write the pointer byte */
packet[offset++] = 0x00;
payload_len = len - 1;
} else {
if (!tsmux_write_ts_header (mux, packet, &section->pi,
section->pi.stream_avail, &len, &offset))
goto fail;
payload_len = len;
map.data[offset++] = 0x00;
len--;
} else if (!tsmux_write_ts_header (mux, map.data, &section->pi,
section->pi.stream_avail, &len, &offset)) {
gst_buffer_unmap (buf, &map);
gst_buffer_unref (buf);
goto done;
}
/* Wrap the TS header and adaption field in a GstMemory */
mem = gst_memory_new_wrapped (GST_MEMORY_FLAG_READONLY,
packet, TSMUX_PACKET_LENGTH, 0, offset, packet, g_free);
GST_DEBUG ("Creating section packet for offset %u with length %u; %u bytes"
" remaining", payload_written, len, section->pi.stream_avail - len);
TS_DEBUG ("Creating packet buffer at offset "
"%" G_GSIZE_FORMAT " with length %u", payload_written, payload_len);
/* If in M2TS mode, we will need to resize to 4 bytes after the end
of the buffer. For performance reasons, we will now try to include
4 extra bytes from the source buffer, then resize down, to avoid
having an extra 4 byte GstMemory appended. If the source buffer
does not have enough data for this, a new GstMemory will be used */
if (gst_buffer_get_size (section_buffer) - (payload_written +
payload_len) >= 4) {
/* enough space */
extra_alloc_bytes = 4;
} else {
extra_alloc_bytes = 0;
}
packet_buffer = gst_buffer_copy_region (section_buffer, GST_BUFFER_COPY_ALL,
payload_written, payload_len + extra_alloc_bytes);
/* Prepend the header to the section data */
gst_buffer_prepend_memory (packet_buffer, mem);
/* add an extra 4 bytes if it could not be reserved already */
if (extra_alloc_bytes == 4) {
/* we allocated those already, resize */
gst_buffer_set_size (packet_buffer,
gst_buffer_get_size (packet_buffer) - extra_alloc_bytes);
} else {
void *ptr = g_malloc (4);
GstMemory *extra =
gst_memory_new_wrapped (GST_MEMORY_FLAG_READONLY, ptr, 4, 0, 0, ptr,
g_free);
gst_buffer_append_memory (packet_buffer, extra);
}
TS_DEBUG ("Writing %d bytes to section. %d bytes remaining",
len, section->pi.stream_avail - len);
memcpy (map.data + offset, data + payload_written, len);
gst_buffer_unmap (buf, &map);
/* Push the packet without PCR */
if (G_UNLIKELY (!tsmux_packet_out (mux, packet_buffer, -1))) {
/* Buffer given away */
packet_buffer = NULL;
goto fail;
}
if (G_UNLIKELY (!tsmux_packet_out (mux, buf, -1)))
goto done;
packet_buffer = NULL;
section->pi.stream_avail -= len;
payload_written += payload_len;
payload_written += len;
section->pi.packet_start_unit_indicator = FALSE;
}
gst_buffer_unref (section_buffer);
ret = TRUE;
return TRUE;
fail:
g_free (packet);
if (section_buffer)
gst_buffer_unref (section_buffer);
return FALSE;
done:
return ret;
}
/**
@ -1301,22 +1249,29 @@ tsmux_send_section (TsMux * mux, GstMpegtsSection * section)
tsmux_section.section = section;
tsmux_section.pi.pid = section->pid;
ret = tsmux_section_write_packet (NULL, &tsmux_section, mux);
ret = tsmux_section_write_packet (mux, &tsmux_section);
gst_mpegts_section_unref (section);
return ret;
}
static void
tsmux_write_si_foreach (gpointer key, gpointer value, gpointer user_data)
{
GstMpegtsSectionType section_type = GPOINTER_TO_INT (key);
TsMuxSection *section = value;
TsMux *mux = user_data;
if (!tsmux_section_write_packet (mux, section))
GST_WARNING ("Failed to send SI section (type %d)", section_type);
}
static gboolean
tsmux_write_si (TsMux * mux)
{
g_hash_table_foreach (mux->si_sections,
(GHFunc) tsmux_section_write_packet, mux);
g_hash_table_foreach (mux->si_sections, tsmux_write_si_foreach, mux);
mux->si_changed = FALSE;
return TRUE;
}
static void
@ -1753,7 +1708,7 @@ tsmux_write_pat (TsMux * mux)
mux->pat_changed = FALSE;
}
return tsmux_section_write_packet (NULL, &mux->pat, mux);
return tsmux_section_write_packet (mux, &mux->pat);
}
static gboolean
@ -1853,7 +1808,7 @@ tsmux_write_pmt (TsMux * mux, TsMuxProgram * program)
program->pmt.section->version_number = program->pmt_version++;
}
return tsmux_section_write_packet (NULL, &program->pmt, mux);
return tsmux_section_write_packet (mux, &program->pmt);
}
static gboolean
@ -1861,7 +1816,7 @@ tsmux_write_scte_null (TsMux * mux, TsMuxProgram * program)
{
/* SCTE-35 NULL section is created when PID is set */
GST_LOG ("Writing SCTE NULL packet");
return tsmux_section_write_packet (NULL, program->scte35_null_section, mux);
return tsmux_section_write_packet (mux, program->scte35_null_section);
}
void