* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavcodec/get_bits.h"
#include "avformat.h"
#include "rtpdec_formats.h"
-#include "libavcodec/get_bits.h"
-#define RTP_H261_PAYLOAD_HEADER_SIZE 4
+#define RTP_H261_PAYLOAD_HEADER_SIZE 4
struct PayloadContext {
AVIOContext *buf;
static av_cold int h261_init(AVFormatContext *ctx, int st_index,
PayloadContext *data)
{
- //av_log(ctx, AV_LOG_DEBUG, "h261_init() for stream %d\n", st_index);
-
if (st_index < 0)
return 0;
return 0;
}
-int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
- AVStream *st, AVPacket *pkt, uint32_t *timestamp,
- const uint8_t *buf, int len, uint16_t seq, int flags)
+static int h261_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_h261_ctx,
+ AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+ const uint8_t *buf, int len, uint16_t seq,
+ int flags)
{
int sbit, ebit, gobn, mbap, quant;
int res;
- /* drop data of previous packets in case of non-continuous (loss) packet stream */
- if (data->buf && data->timestamp != *timestamp) {
- h261_free_dyn_buffer(&data->buf);
+ /* drop data of previous packets in case of non-continuous (lossy) packet stream */
+ if (rtp_h261_ctx->buf && rtp_h261_ctx->timestamp != *timestamp) {
+ h261_free_dyn_buffer(&rtp_h261_ctx->buf);
+ rtp_h261_ctx->endbyte_bits = 0;
}
/* sanity check for size of input packet: 1 byte payload at least */
}
/*
- decode the H.261 payload header according to section 4.1 of RFC 4587:
- (uses 4 bytes between RTP header and H.261 stream per packet)
-
- 0 1 2 3
- 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- |SBIT |EBIT |I|V| GOBN | MBAP | QUANT | HMVD | VMVD |
- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-
- Start bit position (SBIT): 3 bits
- End bit position (EBIT): 3 bits
- INTRA-frame encoded data (I): 1 bit
- Motion Vector flag (V): 1 bit
- GOB number (GOBN): 4 bits
- Macroblock address predictor (MBAP): 5 bits
- Quantizer (QUANT): 5 bits
- Horizontal motion vector data (HMVD): 5 bits
- Vertical motion vector data (VMVD): 5 bits
-
- */
+ * decode the H.261 payload header according to section 4.1 of RFC 4587:
+ * (uses 4 bytes between RTP header and H.261 stream per packet)
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |SBIT |EBIT |I|V| GOBN | MBAP | QUANT | HMVD | VMVD |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Start bit position (SBIT): 3 bits
+ * End bit position (EBIT): 3 bits
+ * INTRA-frame encoded data (I): 1 bit
+ * Motion Vector flag (V): 1 bit
+ * GOB number (GOBN): 4 bits
+ * Macroblock address predictor (MBAP): 5 bits
+ * Quantizer (QUANT): 5 bits
+ * Horizontal motion vector data (HMVD): 5 bits
+ * Vertical motion vector data (VMVD): 5 bits
+ */
sbit = (buf[0] >> 5) & 0x07;
ebit = (buf[0] >> 2) & 0x07;
gobn = (buf[1] >> 4) & 0x0f;
len -= RTP_H261_PAYLOAD_HEADER_SIZE;
/* start frame buffering with new dynamic buffer */
- if (!data->buf) {
- /* sanity check: a new frame starts with gobn=0, sbit=0, mbap=0, uqnat=0 */
- if (!gobn && !sbit && !mbap && !quant){
- res = avio_open_dyn_buf(&data->buf);
+ if (!rtp_h261_ctx->buf) {
+ /* sanity check: a new frame starts with gobn=0, sbit=0, mbap=0, quant=0 */
+ if (!gobn && !sbit && !mbap && !quant) {
+ res = avio_open_dyn_buf(&rtp_h261_ctx->buf);
if (res < 0)
return res;
/* update the timestamp in the frame packet with the one from the RTP packet */
- data->timestamp = *timestamp;
+ rtp_h261_ctx->timestamp = *timestamp;
} else {
/* frame not started yet, need more packets */
return AVERROR(EAGAIN);
}
/* do the "byte merging" at the boundaries of two consecutive frame fragments */
- if (data->endbyte_bits || sbit) {
- if (data->endbyte_bits == sbit) {
- data->endbyte |= buf[0] & (0xff >> sbit);
- data->endbyte_bits = 0;
+ if (rtp_h261_ctx->endbyte_bits || sbit) {
+ if (rtp_h261_ctx->endbyte_bits == sbit) {
+ rtp_h261_ctx->endbyte |= buf[0] & (0xff >> sbit);
+ rtp_h261_ctx->endbyte_bits = 0;
buf++;
len--;
- avio_w8(data->buf, data->endbyte);
+ avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);
} else {
/* ebit/sbit values inconsistent, assuming packet loss */
GetBitContext gb;
init_get_bits(&gb, buf, len*8 - ebit);
skip_bits(&gb, sbit);
- if (data->endbyte_bits) {
- data->endbyte |= get_bits(&gb, 8 - data->endbyte_bits);
- avio_w8(data->buf, data->endbyte);
+ if (rtp_h261_ctx->endbyte_bits) {
+ rtp_h261_ctx->endbyte |= get_bits(&gb, 8 - rtp_h261_ctx->endbyte_bits);
+ avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);
}
while (get_bits_left(&gb) >= 8)
- avio_w8(data->buf, get_bits(&gb, 8));
- data->endbyte_bits = get_bits_left(&gb);
- if (data->endbyte_bits)
- data->endbyte = get_bits(&gb, data->endbyte_bits) <<
- (8 - data->endbyte_bits);
+ avio_w8(rtp_h261_ctx->buf, get_bits(&gb, 8));
+ rtp_h261_ctx->endbyte_bits = get_bits_left(&gb);
+ if (rtp_h261_ctx->endbyte_bits)
+ rtp_h261_ctx->endbyte = get_bits(&gb, rtp_h261_ctx->endbyte_bits) <<
+ (8 - rtp_h261_ctx->endbyte_bits);
ebit = 0;
- len = 0;
+ len = 0;
}
}
if (ebit) {
if (len > 0)
- avio_write(data->buf, buf, len - 1);
- data->endbyte_bits = 8 - ebit;
- data->endbyte = buf[len - 1] & (0xff << ebit);
+ avio_write(rtp_h261_ctx->buf, buf, len - 1);
+ rtp_h261_ctx->endbyte_bits = 8 - ebit;
+ rtp_h261_ctx->endbyte = buf[len - 1] & (0xff << ebit);
} else {
- avio_write(data->buf, buf, len);
+ avio_write(rtp_h261_ctx->buf, buf, len);
}
/* RTP marker bit means: last fragment of current frame was received;
return AVERROR(EAGAIN);
/* write the completed last byte from the "byte merging" */
- if (data->endbyte_bits)
- avio_w8(data->buf, data->endbyte);
- data->endbyte_bits = 0;
+ if (rtp_h261_ctx->endbyte_bits)
+ avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);
+ rtp_h261_ctx->endbyte_bits = 0;
/* close frame buffering and create resulting A/V packet */
- res = ff_rtp_finalize_packet(pkt, &data->buf, st->index);
+ res = ff_rtp_finalize_packet(pkt, &rtp_h261_ctx->buf, st->index);
if (res < 0)
return res;
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_H261,
.init = h261_init,
- .parse_packet = ff_h261_handle_packet,
.alloc = h261_new_context,
.free = h261_free_context,
+ .parse_packet = h261_handle_packet,
.static_payload_id = 31,
};
projects / ffmpeg / blobdiff