static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq,
int flags)
{
uint8_t type, q, width, height;
const uint8_t *qtables = NULL;
uint16_t qtable_len;
uint32_t off;
int ret, dri = 0;
if (len < 8) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
/* Parse the main JPEG header. */
off = AV_RB24(buf + 1); /* fragment byte offset */
type = AV_RB8(buf + 4); /* id of jpeg decoder params */
q = AV_RB8(buf + 5); /* quantization factor (or table id) */
width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
buf += 8;
len -= 8;
if (type & 0x40) {
if (len < 4) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
dri = AV_RB16(buf);
buf += 4;
len -= 4;
type &= ~0x40;
}
/* Parse the restart marker header. */
if (type > 63) {
av_log(ctx, AV_LOG_ERROR,
"Unimplemented RTP/JPEG restart marker header.\n");
return AVERROR_PATCHWELCOME;
}
if (type > 1) {
av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
return AVERROR_PATCHWELCOME;
}
/* Parse the quantization table header. */
if (off == 0) {
/* Start of JPEG data packet. */
uint8_t new_qtables[128];
uint8_t hdr[1024];
if (q > 127) {
uint8_t precision;
if (len < 4) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
/* The first byte is reserved for future use. */
precision = AV_RB8(buf + 1); /* size of coefficients */
qtable_len = AV_RB16(buf + 2); /* length in bytes */
buf += 4;
len -= 4;
if (precision)
av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
if (qtable_len > 0) {
if (len < qtable_len) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
qtables = buf;
buf += qtable_len;
len -= qtable_len;
if (q < 255) {
if (jpeg->qtables_len[q - 128] &&
(jpeg->qtables_len[q - 128] != qtable_len ||
memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
av_log(ctx, AV_LOG_WARNING,
"Quantization tables for q=%d changed\n", q);
} else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
memcpy(&jpeg->qtables[q - 128][0], qtables,
qtable_len);
jpeg->qtables_len[q - 128] = qtable_len;
}
}
} else {
if (q == 255) {
av_log(ctx, AV_LOG_ERROR,
"Invalid RTP/JPEG packet. Quantization tables not found.\n");
return AVERROR_INVALIDDATA;
}
if (!jpeg->qtables_len[q - 128]) {
av_log(ctx, AV_LOG_ERROR,
"No quantization tables known for q=%d yet.\n", q);
return AVERROR_INVALIDDATA;
}
qtables = &jpeg->qtables[q - 128][0];
qtable_len = jpeg->qtables_len[q - 128];
}
} else { /* q <= 127 */
if (q == 0 || q > 99) {
av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
return AVERROR_INVALIDDATA;
}
create_default_qtables(new_qtables, q);
qtables = new_qtables;
qtable_len = sizeof(new_qtables);
}
/* Skip the current frame in case of the end packet
* has been lost somewhere. */
free_frame_if_needed(jpeg);
if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
return ret;
jpeg->timestamp = *timestamp;
/* Generate a frame and scan headers that can be prepended to the
* RTP/JPEG data payload to produce a JPEG compressed image in
* interchange format. */
jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
height, qtables,
qtable_len / 64, dri);
/* Copy JPEG header to frame buffer. */
avio_write(jpeg->frame, hdr, jpeg->hdr_size);
}
if (!jpeg->frame) {
av_log(ctx, AV_LOG_ERROR,
"Received packet without a start chunk; dropping frame.\n");
return AVERROR(EAGAIN);
}
if (jpeg->timestamp != *timestamp) {
/* Skip the current frame if timestamp is incorrect.
* A start packet has been lost somewhere. */
free_frame_if_needed(jpeg);
av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
return AVERROR_INVALIDDATA;
}
if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
av_log(ctx, AV_LOG_ERROR,
"Missing packets; dropping frame.\n");
return AVERROR(EAGAIN);
}
/* Copy data to frame buffer. */
avio_write(jpeg->frame, buf, len);
if (flags & RTP_FLAG_MARKER) {
/* End of JPEG data packet. */
uint8_t buf[2] = { 0xff, EOI };
/* Put EOI marker. */
avio_write(jpeg->frame, buf, sizeof(buf));
/* Prepare the JPEG packet. */
if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error occurred when getting frame buffer.\n");
return ret;
}
return 0;
}
return AVERROR(EAGAIN);
}
static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, int flags)
{
uint8_t type, q, width, height;
const uint8_t *qtables = NULL;
uint16_t qtable_len;
uint32_t off;
int ret;
if (len < 8) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
/* Parse the main JPEG header. */
off = AV_RB24(buf + 1); /* fragment byte offset */
type = AV_RB8(buf + 4); /* id of jpeg decoder params */
q = AV_RB8(buf + 5); /* quantization factor (or table id) */
width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
buf += 8;
len -= 8;
/* Parse the restart marker header. */
if (type > 63) {
av_log(ctx, AV_LOG_ERROR,
"Unimplemented RTP/JPEG restart marker header.\n");
return AVERROR_PATCHWELCOME;
}
/* Parse the quantization table header. */
if (q > 127 && off == 0) {
uint8_t precision;
if (len < 4) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
/* The first byte is reserved for future use. */
precision = AV_RB8(buf + 1); /* size of coefficients */
qtable_len = AV_RB16(buf + 2); /* length in bytes */
buf += 4;
len -= 4;
if (precision)
av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
if (q == 255 && qtable_len == 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid RTP/JPEG packet. Quantization tables not found.\n");
return AVERROR_INVALIDDATA;
}
if (qtable_len > 0) {
if (len < qtable_len) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
qtables = buf;
buf += qtable_len;
len -= qtable_len;
}
}
if (off == 0) {
/* Start of JPEG data packet. */
uint8_t new_qtables[128];
uint8_t hdr[1024];
/* Skip the current frame in case of the end packet
* has been lost somewhere. */
free_frame_if_needed(jpeg);
if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
return ret;
jpeg->timestamp = *timestamp;
if (!qtables) {
create_default_qtables(new_qtables, q);
qtables = new_qtables;
qtable_len = sizeof(new_qtables);
}
/* Generate a frame and scan headers that can be prepended to the
* RTP/JPEG data payload to produce a JPEG compressed image in
* interchange format. */
jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
height, qtables,
qtable_len > 64 ? 2 : 1);
/* Copy JPEG header to frame buffer. */
avio_write(jpeg->frame, hdr, jpeg->hdr_size);
}
if (!jpeg->frame) {
av_log(ctx, AV_LOG_ERROR,
"Received packet without a start chunk; dropping frame.\n");
return AVERROR(EAGAIN);
}
if (jpeg->timestamp != *timestamp) {
/* Skip the current frame if timestamp is incorrect.
* A start packet has been lost somewhere. */
free_frame_if_needed(jpeg);
av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
return AVERROR_INVALIDDATA;
}
if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
av_log(ctx, AV_LOG_ERROR,
"Missing packets; dropping frame.\n");
return AVERROR(EAGAIN);
}
/* Copy data to frame buffer. */
avio_write(jpeg->frame, buf, len);
if (flags & RTP_FLAG_MARKER) {
/* End of JPEG data packet. */
PutBitContext pbc;
uint8_t buf[2];
/* Put EOI marker. */
init_put_bits(&pbc, buf, sizeof(buf));
put_marker(&pbc, EOI);
flush_put_bits(&pbc);
avio_write(jpeg->frame, buf, sizeof(buf));
/* Prepare the JPEG packet. */
av_init_packet(pkt);
pkt->size = avio_close_dyn_buf(jpeg->frame, &pkt->data);
if (pkt->size < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error occured when getting frame buffer.\n");
jpeg->frame = NULL;
return pkt->size;
}
pkt->stream_index = st->index;
pkt->destruct = av_destruct_packet;
/* Re-init the frame buffer. */
jpeg->frame = NULL;
return 0;
}
return AVERROR(EAGAIN);
}
