* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include "avcodec.h"
#include "bsf.h"
+#include "bsf_internal.h"
+#include "internal.h"
#include "mpeg4video.h"
typedef struct UnpackBFramesBSFContext {
- AVPacket *b_frame;
+ AVBufferRef *b_frame_ref;
} UnpackBFramesBSFContext;
-/* search next start code */
-static unsigned int find_startcode(const uint8_t *buf, int buf_size, int *pos)
-{
- unsigned int startcode = 0xFF;
-
- for (; *pos < buf_size;) {
- startcode = ((startcode << 8) | buf[*pos]) & 0xFFFFFFFF;
- *pos +=1;
- if ((startcode & 0xFFFFFF00) != 0x100)
- continue; /* no startcode */
- return startcode;
- }
-
- return 0;
-}
-
/* determine the position of the packed marker in the userdata,
* the number of VOPs and the position of the second VOP */
static void scan_buffer(const uint8_t *buf, int buf_size,
int *pos_p, int *nb_vop, int *pos_vop2) {
- unsigned int startcode;
- int pos, i;
+ uint32_t startcode;
+ const uint8_t *end = buf + buf_size, *pos = buf;
- for (pos = 0; pos < buf_size;) {
- startcode = find_startcode(buf, buf_size, &pos);
+ while (pos < end) {
+ startcode = -1;
+ pos = avpriv_find_start_code(pos, end, &startcode);
if (startcode == USER_DATA_STARTCODE && pos_p) {
/* check if the (DivX) userdata string ends with 'p' (packed) */
- for (i = 0; i < 255 && pos + i + 1 < buf_size; i++) {
- if (buf[pos + i] == 'p' && buf[pos + i + 1] == '\0') {
- *pos_p = pos + i;
+ for (int i = 0; i < 255 && pos + i + 1 < end; i++) {
+ if (pos[i] == 'p' && pos[i + 1] == '\0') {
+ *pos_p = pos + i - buf;
break;
}
}
} else if (startcode == VOP_STARTCODE && nb_vop) {
*nb_vop += 1;
if (*nb_vop == 2 && pos_vop2) {
- *pos_vop2 = pos - 4; /* subtract 4 bytes startcode */
+ *pos_vop2 = pos - buf - 4; /* subtract 4 bytes startcode */
}
}
}
}
-static int mpeg4_unpack_bframes_filter(AVBSFContext *ctx, AVPacket *out)
+static int mpeg4_unpack_bframes_filter(AVBSFContext *ctx, AVPacket *pkt)
{
UnpackBFramesBSFContext *s = ctx->priv_data;
int pos_p = -1, nb_vop = 0, pos_vop2 = -1, ret = 0;
- AVPacket *in;
- ret = ff_bsf_get_packet(ctx, &in);
+ ret = ff_bsf_get_packet_ref(ctx, pkt);
if (ret < 0)
return ret;
- scan_buffer(in->data, in->size, &pos_p, &nb_vop, &pos_vop2);
+ scan_buffer(pkt->data, pkt->size, &pos_p, &nb_vop, &pos_vop2);
av_log(ctx, AV_LOG_DEBUG, "Found %d VOP startcode(s) in this packet.\n", nb_vop);
if (pos_vop2 >= 0) {
- if (s->b_frame->data) {
+ if (s->b_frame_ref) {
av_log(ctx, AV_LOG_WARNING,
"Missing one N-VOP packet, discarding one B-frame.\n");
- av_packet_unref(s->b_frame);
+ av_buffer_unref(&s->b_frame_ref);
}
- /* store the packed B-frame in the BSFContext */
- ret = av_packet_ref(s->b_frame, in);
- if (ret < 0) {
+ /* store a reference to the packed B-frame's data in the BSFContext */
+ s->b_frame_ref = av_buffer_ref(pkt->buf);
+ if (!s->b_frame_ref) {
+ ret = AVERROR(ENOMEM);
goto fail;
}
- s->b_frame->size -= pos_vop2;
- s->b_frame->data += pos_vop2;
+ s->b_frame_ref->data = pkt->data + pos_vop2;
+ s->b_frame_ref->size = pkt->size - pos_vop2;
}
if (nb_vop > 2) {
"Found %d VOP headers in one packet, only unpacking one.\n", nb_vop);
}
- if (nb_vop == 1 && s->b_frame->data) {
- /* use frame from BSFContext */
- av_packet_move_ref(out, s->b_frame);
+ if (nb_vop == 1 && s->b_frame_ref) {
+ AVBufferRef *tmp = pkt->buf;
- /* use properties from current input packet */
- ret = av_packet_copy_props(out, in);
- if (ret < 0) {
- goto fail;
- }
+ /* make tmp accurately reflect the packet's data */
+ tmp->data = pkt->data;
+ tmp->size = pkt->size;
+
+ /* replace data in packet with stored data */
+ pkt->buf = s->b_frame_ref;
+ pkt->data = s->b_frame_ref->data;
+ pkt->size = s->b_frame_ref->size;
- if (in->size <= MAX_NVOP_SIZE) {
- /* N-VOP */
+ /* store reference to data into BSFContext */
+ s->b_frame_ref = tmp;
+
+ if (s->b_frame_ref->size <= MAX_NVOP_SIZE) {
+ /* N-VOP - discard stored data */
av_log(ctx, AV_LOG_DEBUG, "Skipping N-VOP.\n");
- } else {
- /* copy packet into BSFContext */
- av_packet_move_ref(s->b_frame, in);
+ av_buffer_unref(&s->b_frame_ref);
}
} else if (nb_vop >= 2) {
/* use first frame of the packet */
- av_packet_move_ref(out, in);
- out->size = pos_vop2;
+ pkt->size = pos_vop2;
} else if (pos_p >= 0) {
- ret = av_packet_make_writable(in);
+ ret = av_packet_make_writable(pkt);
if (ret < 0)
goto fail;
av_log(ctx, AV_LOG_DEBUG, "Updating DivX userdata (remove trailing 'p').\n");
- av_packet_move_ref(out, in);
/* remove 'p' (packed) from the end of the (DivX) userdata string */
- out->data[pos_p] = '\0';
+ pkt->data[pos_p] = '\0';
} else {
- /* copy packet */
- av_packet_move_ref(out, in);
+ /* use packet as is */
}
fail:
if (ret < 0)
- av_packet_unref(out);
- av_packet_free(&in);
+ av_packet_unref(pkt);
return ret;
}
static int mpeg4_unpack_bframes_init(AVBSFContext *ctx)
{
- UnpackBFramesBSFContext *s = ctx->priv_data;
-
- s->b_frame = av_packet_alloc();
- if (!s->b_frame)
- return AVERROR(ENOMEM);
-
if (ctx->par_in->extradata) {
int pos_p_ext = -1;
scan_buffer(ctx->par_in->extradata, ctx->par_in->extradata_size, &pos_p_ext, NULL, NULL);
return 0;
}
-static void mpeg4_unpack_bframes_flush(AVBSFContext *bsfc)
-{
- UnpackBFramesBSFContext *ctx = bsfc->priv_data;
- av_packet_unref(ctx->b_frame);
-}
-
-static void mpeg4_unpack_bframes_close(AVBSFContext *bsfc)
+static void mpeg4_unpack_bframes_close_flush(AVBSFContext *bsfc)
{
UnpackBFramesBSFContext *ctx = bsfc->priv_data;
- av_packet_free(&ctx->b_frame);
+ av_buffer_unref(&ctx->b_frame_ref);
}
static const enum AVCodecID codec_ids[] = {
.priv_data_size = sizeof(UnpackBFramesBSFContext),
.init = mpeg4_unpack_bframes_init,
.filter = mpeg4_unpack_bframes_filter,
- .flush = mpeg4_unpack_bframes_flush,
- .close = mpeg4_unpack_bframes_close,
+ .flush = mpeg4_unpack_bframes_close_flush,
+ .close = mpeg4_unpack_bframes_close_flush,
.codec_ids = codec_ids,
};
projects / ffmpeg / blobdiff