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mpeg2: add decode_packet() helper function.

Browse source 
Split decode_buffer() into the core infrastructure that determines
the packets contained in the adapter and the actual function that
decodes the packet data.
This commit is contained in:
Gwenole Beauchesne 2012-10-10 09:45:03 +02:00
parent dc03ca9100
commit 388e881ba9
1 changed files with 87 additions and 76 deletions
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163
gst-libs/gst/vaapi/gstvaapidecoder_mpeg2.c
View file

@ -945,6 +945,92 @@ scan_for_start_code(GstAdapter *adapter, guint ofs, guint size, guint32 *scp)
scp);
}
static GstVaapiDecoderStatus
decode_packet(GstVaapiDecoderMpeg2 *decoder, guchar *buf, guint buf_size)
{
GstVaapiDecoderMpeg2Private * const priv = decoder->priv;
GstVaapiDecoderStatus status;
guchar type;
/* The packet defined by buf and buf_size contains the start code */
type = buf[3];
switch (type) {
case GST_MPEG_VIDEO_PACKET_PICTURE:
if (!priv->width || !priv->height)
goto unknown_picture_size;
status = decode_picture(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_SEQUENCE:
status = decode_sequence(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_EXTENSION: {
const guchar id = buf[4] >> 4;
switch (id) {
case GST_MPEG_VIDEO_PACKET_EXT_SEQUENCE:
status = decode_sequence_ext(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_EXT_QUANT_MATRIX:
status = decode_quant_matrix_ext(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_EXT_PICTURE:
if (!priv->width || !priv->height)
goto unknown_picture_size;
status = decode_picture_ext(decoder, buf, buf_size);
break;
default:
// Ignore unknown start-code extensions
GST_WARNING("unsupported start code extension (0x%02x)", id);
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
}
break;
}
case GST_MPEG_VIDEO_PACKET_SEQUENCE_END:
status = decode_sequence_end(decoder);
break;
case GST_MPEG_VIDEO_PACKET_GOP:
status = decode_gop(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_USER_DATA:
// Ignore user-data packets
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
default:
if (type >= GST_MPEG_VIDEO_PACKET_SLICE_MIN &&
type <= GST_MPEG_VIDEO_PACKET_SLICE_MAX) {
if (!priv->current_picture)
goto undefined_picture;
status = decode_slice(
decoder,
type - GST_MPEG_VIDEO_PACKET_SLICE_MIN,
buf, buf_size
);
break;
}
else if (type >= 0xb9 && type <= 0xff) {
// Ignore system start codes (PES headers)
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
}
GST_WARNING("unsupported start code (0x%02x)", type);
status = GST_VAAPI_DECODER_STATUS_ERROR_BITSTREAM_PARSER;
break;
}
return status;
unknown_picture_size:
// Ignore packet while picture size is undefined
// i.e. missing sequence headers, or not parsed correctly
GST_WARNING("failed to parse picture of unknown size");
return GST_VAAPI_DECODER_STATUS_SUCCESS;
undefined_picture:
// Ignore packet while picture is undefined
// i.e. missing picture headers, or not parsed correctly
GST_WARNING("failed to parse slice with undefined picture");
return GST_VAAPI_DECODER_STATUS_SUCCESS;
}
static GstVaapiDecoderStatus
decode_buffer(GstVaapiDecoderMpeg2 *decoder, GstBuffer *buffer)
{
@ -954,7 +1040,6 @@ decode_buffer(GstVaapiDecoderMpeg2 *decoder, GstBuffer *buffer)
guchar *buf;
guint buf_size, size;
guint32 start_code;
guint8 type;
gint ofs;
buf = GST_BUFFER_DATA(buffer);
@ -998,82 +1083,8 @@ decode_buffer(GstVaapiDecoderMpeg2 *decoder, GstBuffer *buffer)
buf = GST_BUFFER_DATA(buffer);
buf_size = GST_BUFFER_SIZE(buffer);
status = decode_packet(decoder, buf, buf_size);
type = start_code & 0xff;
switch (type) {
case GST_MPEG_VIDEO_PACKET_PICTURE:
if (priv->width > 0 && priv->height > 0) {
status = decode_picture(decoder, buf, buf_size);
break;
}
// Ignore packet while picture size is undefined
// i.e. missing sequence headers, or not parsed correctly
skip_picture_unknown_size:
GST_WARNING("failed to parse picture of unknown size");
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
case GST_MPEG_VIDEO_PACKET_SEQUENCE:
status = decode_sequence(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_EXTENSION: {
const guchar id = buf[4] >> 4;
switch (id) {
case GST_MPEG_VIDEO_PACKET_EXT_SEQUENCE:
status = decode_sequence_ext(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_EXT_QUANT_MATRIX:
status = decode_quant_matrix_ext(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_EXT_PICTURE:
if (priv->width > 0 && priv->height > 0) {
status = decode_picture_ext(decoder, buf, buf_size);
break;
}
goto skip_picture_unknown_size;
default:
// Ignore unknown extensions
GST_WARNING("unsupported start-code extension (0x%02x)", id);
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
}
break;
}
case GST_MPEG_VIDEO_PACKET_SEQUENCE_END:
status = decode_sequence_end(decoder);
break;
case GST_MPEG_VIDEO_PACKET_GOP:
status = decode_gop(decoder, buf, buf_size);
break;
case GST_MPEG_VIDEO_PACKET_USER_DATA:
// Ignore user-data packets
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
default:
if (type >= GST_MPEG_VIDEO_PACKET_SLICE_MIN &&
type <= GST_MPEG_VIDEO_PACKET_SLICE_MAX) {
if (!priv->current_picture) {
// Ignore packet while picture is undefined
// i.e. missing picture headers, or not parsed correctly
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
}
status = decode_slice(
decoder,
type - GST_MPEG_VIDEO_PACKET_SLICE_MIN,
buf, buf_size
);
break;
}
else if (type >= 0xb9 && type <= 0xff) {
// Ignore system start codes (PES headers)
status = GST_VAAPI_DECODER_STATUS_SUCCESS;
break;
}
GST_WARNING("unsupported start code (0x%02x)", type);
status = GST_VAAPI_DECODER_STATUS_ERROR_BITSTREAM_PARSER;
break;
}
gst_buffer_unref(buffer);
} while (status == GST_VAAPI_DECODER_STATUS_SUCCESS);