static int extract_extradata_mpeg4(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size)
{
ExtractExtradataContext *s = ctx->priv_data;
const uint8_t *ptr = pkt->data, *end = pkt->data + pkt->size;
uint32_t state = UINT32_MAX;
while (ptr < end) {
ptr = avpriv_find_start_code(ptr, end, &state);
if (state == 0x1B3 || state == 0x1B6) {
if (ptr - pkt->data > 4) {
*size = ptr - 4 - pkt->data;
*data = av_malloc(*size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!*data)
return AVERROR(ENOMEM);
memcpy(*data, pkt->data, *size);
if (s->remove) {
pkt->data += *size;
pkt->size -= *size;
}
}
break;
}
}
return 0;
}
static int extract_extradata_vc1(AVBSFContext *ctx, AVPacket *pkt,
uint8_t **data, int *size)
{
ExtractExtradataContext *s = ctx->priv_data;
const uint8_t *ptr = pkt->data, *end = pkt->data + pkt->size;
uint32_t state = UINT32_MAX;
int has_extradata = 0, extradata_size = 0;
while (ptr < end) {
ptr = avpriv_find_start_code(ptr, end, &state);
if (state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT) {
has_extradata = 1;
} else if (has_extradata && IS_MARKER(state)) {
extradata_size = ptr - 4 - pkt->data;
break;
}
}
if (extradata_size) {
*data = av_malloc(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!*data)
return AVERROR(ENOMEM);
memcpy(*data, pkt->data, extradata_size);
*size = extradata_size;
if (s->remove) {
pkt->data += extradata_size;
pkt->size -= extradata_size;
}
}
return 0;
}
/**
* Find the end of the current frame in the bitstream.
* @return the position of the first byte of the next frame, or -1
*/
int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
{
int i;
uint32_t state = pc->state;
/* EOF considered as end of frame */
if (buf_size == 0)
return 0;
/*
0 frame start -> 1/4
1 first_SEQEXT -> 0/2
2 first field start -> 3/0
3 second_SEQEXT -> 2/0
4 searching end
*/
for (i = 0; i < buf_size; i++) {
av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
if (pc->frame_start_found & 1) {
if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
pc->frame_start_found--;
else if (state == EXT_START_CODE + 2) {
if ((buf[i] & 3) == 3)
pc->frame_start_found = 0;
else
pc->frame_start_found = (pc->frame_start_found + 1) & 3;
}
state++;
} else {
i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
i++;
pc->frame_start_found = 4;
}
if (state == SEQ_END_CODE) {
pc->frame_start_found = 0;
pc->state=-1;
return i+1;
}
if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
pc->frame_start_found = 0;
if (pc->frame_start_found < 4 && state == EXT_START_CODE)
pc->frame_start_found++;
if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
pc->frame_start_found = 0;
pc->state = -1;
return i - 3;
}
}
if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
ff_fetch_timestamp(s, i - 3, 1);
}
}
}
pc->state = state;
return END_NOT_FOUND;
}
int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
{
uint32_t state = -1;
const uint8_t *ptr = buf, *end = buf + buf_size;
while (ptr < end) {
ptr = avpriv_find_start_code(ptr, end, &state);
if (state == 0x1B3 || state == 0x1B6)
return ptr - 4 - buf;
}
return 0;
}
static int vc1_split(AVCodecContext *avctx,
const uint8_t *buf, int buf_size)
{
uint32_t state = -1;
int charged = 0;
const uint8_t *ptr = buf, *end = buf + buf_size;
while (ptr < end) {
ptr = avpriv_find_start_code(ptr, end, &state);
if (state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT) {
charged = 1;
} else if (charged && IS_MARKER(state))
return ptr - 4 - buf;
}
return 0;
}
const uint8_t* CheckForEndOfSequence(AVCodecID codec, const uint8_t *buf, long len, uint32_t *state)
{
if (buf && len > 0) {
const uint8_t *p = buf, *end = buf + len;
if (codec == AV_CODEC_ID_MPEG2VIDEO) {
while (p < end) {
p = avpriv_find_start_code(p, end, state);
if (*state == 0x000001b7) {
DbgLog((LOG_TRACE, 50, L"Found SEQ_END_CODE at %p (end: %p)", p, end));
return p;
}
}
}
return NULL;
}
return NULL;
}
int CheckForSequenceMarkers(AVCodecID codec, const uint8_t *buf, long len, uint32_t *state, const uint8_t **pos)
{
int status = 0;
if (buf && len > 0) {
const uint8_t *p = buf, *end = buf + len;
if (codec == AV_CODEC_ID_MPEG2VIDEO) {
while (p < end) {
p = avpriv_find_start_code(p, end, state);
if (*state == 0x000001b7) {
DbgLog((LOG_TRACE, 50, L"Found SEQ_END_CODE at %p (end: %p)", p, end));
status |= STATE_EOS_FOUND;
if (pos)
*pos = p;
return status;
} else if (*state == 0x000001b8) {
status |= STATE_GOP_FOUND;
}
}
}
return status;
}
return status;
}