This is the result of me screwing around to see how complex of a task this
would be; the answer is evidently "not particularly complex". I seem to have
at least a few issues to work out, since the .ts files I'm generating don't
always seek correctly, but it's a start.
Would appreciate it if anyone who knows a bit more about how AVC and HEVC
differ here could provide some guidance on what's left to do.
---
libavcodec/h264_mp4toannexb_bsf.c | 126 ++++++++++++++++++++++++--------------
1 file changed, 81 insertions(+), 45 deletions(-)
diff --git a/libavcodec/h264_mp4toannexb_bsf.c
b/libavcodec/h264_mp4toannexb_bsf.c
index ae96ee9..7cf8bc2 100644
--- a/libavcodec/h264_mp4toannexb_bsf.c
+++ b/libavcodec/h264_mp4toannexb_bsf.c
@@ -32,6 +32,7 @@ typedef struct H264BSFContext {
uint8_t new_idr;
uint8_t idr_sps_seen;
uint8_t idr_pps_seen;
+ uint8_t idr_vps_seen;
int extradata_parsed;
} H264BSFContext;
@@ -63,56 +64,83 @@ static int alloc_and_copy(uint8_t **poutbuf, int
*poutbuf_size,
return 0;
}
+#define NAL_SPS 33
+#define NAL_PPS 34
+
static int h264_extradata_to_annexb(H264BSFContext *ctx, AVCodecContext
*avctx, const int padding)
{
- uint16_t unit_size;
+ int hevc = avctx->codec_id == AV_CODEC_ID_HEVC;
+ uint16_t unit_size, unit_nb;
uint64_t total_size = 0;
- uint8_t *out = NULL, unit_nb, sps_done = 0,
- sps_seen = 0, pps_seen = 0;
- const uint8_t *extradata = avctx->extradata + 4;
+ uint8_t *out = NULL, sps_done = 0,
+ sps_seen = 0, pps_seen = 0, set_nb;
+ const uint8_t *extradata = avctx->extradata + (hevc ? 21 : 4);
static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
ctx->sps_offset = ctx->pps_offset = -1;
- /* retrieve sps and pps unit(s) */
- unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
- if (!unit_nb) {
- goto pps;
- } else {
- ctx->sps_offset = 0;
- sps_seen = 1;
- }
-
- while (unit_nb--) {
- int err;
+ set_nb = hevc ? *extradata++ : 1;
- unit_size = AV_RB16(extradata);
- total_size += unit_size + 4;
- if (total_size > INT_MAX - padding) {
- av_log(avctx, AV_LOG_ERROR,
- "Too big extradata size, corrupted stream or invalid
MP4/AVCC bitstream\n");
- av_free(out);
- return AVERROR(EINVAL);
- }
- if (extradata + 2 + unit_size > avctx->extradata +
avctx->extradata_size) {
- av_log(avctx, AV_LOG_ERROR, "Packet header is not contained in
global extradata, "
- "corrupted stream or invalid MP4/AVCC bitstream\n");
- av_free(out);
- return AVERROR(EINVAL);
- }
- if ((err = av_reallocp(&out, total_size + padding)) < 0)
- return err;
- memcpy(out + total_size - unit_size - 4, nalu_header, 4);
- memcpy(out + total_size - unit_size, extradata + 2, unit_size);
- extradata += 2 + unit_size;
-pps:
- if (!unit_nb && !sps_done++) {
- unit_nb = *extradata++; /* number of pps unit(s) */
- if (unit_nb) {
- ctx->pps_offset = (extradata - 1) - (avctx->extradata + 4);
+ while (set_nb--) {
+ int type = hevc ? *extradata++ & 0x3f : 0;
+ /* retrieve sps and pps unit(s) */
+ if (hevc) {
+ unit_nb = AV_RB16(extradata);
+ extradata += 2;
+ if (type == NAL_SPS) {
+ ctx->sps_offset = total_size;
+ sps_seen = 1;
+ } else if (type == NAL_PPS) {
+ ctx->pps_offset = total_size;
pps_seen = 1;
}
+ } else {
+ unit_nb = *extradata++ & 0x1f; /* number of units */
+ if (!unit_nb) {
+ type = NAL_PPS;
+ goto pps;
+ } else {
+ type = NAL_SPS;
+ ctx->sps_offset = 0;
+ sps_seen = 1;
+ }
+ }
+
+ while (unit_nb--) {
+ int err;
+
+ unit_size = AV_RB16(extradata);
+ if (type == NAL_SPS || type == NAL_PPS || !hevc) {
+ if (!hevc)
+ ctx->sps_offset = total_size;
+ total_size += unit_size + 4;
+ if (total_size > INT_MAX - padding) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Too big extradata size, corrupted stream or
invalid MP4/AVCC bitstream\n");
+ av_free(out);
+ return AVERROR(EINVAL);
+ }
+ if (extradata + 2 + unit_size > avctx->extradata +
avctx->extradata_size) {
+ av_log(avctx, AV_LOG_ERROR, "Packet header is not
contained in global extradata, "
+ "corrupted stream or invalid MP4/AVCC bitstream\n");
+ av_free(out);
+ return AVERROR(EINVAL);
+ }
+ if ((err = av_reallocp(&out, total_size + padding)) < 0)
+ return err;
+ memcpy(out + total_size - unit_size - 4, nalu_header, 4);
+ memcpy(out + total_size - unit_size, extradata + 2, unit_size);
+ }
+ extradata += 2 + unit_size;
+ pps:
+ if (!hevc && !unit_nb && !sps_done++) {
+ unit_nb = *extradata++; /* number of pps unit(s) */
+ if (unit_nb) {
+ ctx->pps_offset = (extradata - 1) - (avctx->extradata + 4);
+ pps_seen = 1;
+ }
+ }
}
}
@@ -143,12 +171,18 @@ static int
h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
int keyframe)
{
H264BSFContext *ctx = bsfc->priv_data;
+ int hevc = avctx->codec_id == AV_CODEC_ID_HEVC;
int i;
uint8_t unit_type;
int32_t nal_size;
uint32_t cumul_size = 0;
const uint8_t *buf_end = buf + buf_size;
int ret = 0;
+ uint8_t vps_type = hevc ? 32 : 0;
+ uint8_t sps_type = hevc ? 33 : 7;
+ uint8_t pps_type = hevc ? 34 : 8;
+ uint8_t idr_type = hevc ? 19 : 5;
+ uint8_t idr_type2 = hevc ? 20 : 5;
/* nothing to filter */
if (!avctx->extradata || avctx->extradata_size < 6) {
@@ -180,14 +214,16 @@ static int
h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
nal_size = (nal_size << 8) | buf[i];
buf += ctx->length_size;
- unit_type = *buf & 0x1f;
+ unit_type = hevc ? (*buf >> 1) & 0x3f : *buf & 0x1f;
if (buf + nal_size > buf_end || nal_size < 0)
goto fail;
- if (unit_type == 7)
+ if (unit_type == vps_type)
+ ctx->idr_vps_seen = ctx->new_idr = 1;
+ else if (unit_type == sps_type)
ctx->idr_sps_seen = ctx->new_idr = 1;
- else if (unit_type == 8) {
+ else if (unit_type == pps_type) {
ctx->idr_pps_seen = ctx->new_idr = 1;
/* if SPS has not been seen yet, prepend the AVCC one to PPS */
if (!ctx->idr_sps_seen) {
@@ -208,18 +244,18 @@ static int
h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
/* if this is a new IDR picture following an IDR picture, reset the
idr flag.
* Just check first_mb_in_slice to be 0 as this is the simplest
solution.
* This could be checking idr_pic_id instead, but would complexify the
parsing. */
- if (!ctx->new_idr && unit_type == 5 && (buf[1] & 0x80))
+ if (!ctx->new_idr && (unit_type == idr_type || unit_type == idr_type2)
&& (buf[1] & 0x80))
ctx->new_idr = 1;
/* prepend only to the first type 5 NAL unit of an IDR picture, if no
sps/pps are already present */
- if (ctx->new_idr && unit_type == 5 && !ctx->idr_sps_seen &&
!ctx->idr_pps_seen) {
+ if (ctx->new_idr && (unit_type == idr_type || unit_type == idr_type2)
&& !ctx->idr_sps_seen && !ctx->idr_pps_seen) {
if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
avctx->extradata, avctx->extradata_size,
buf, nal_size)) < 0)
goto fail;
ctx->new_idr = 0;
/* if only SPS has been seen, also insert PPS */
- } else if (ctx->new_idr && unit_type == 5 && ctx->idr_sps_seen &&
!ctx->idr_pps_seen) {
+ } else if (ctx->new_idr && (unit_type == idr_type || unit_type ==
idr_type2) && ctx->idr_sps_seen && !ctx->idr_pps_seen) {
if (ctx->pps_offset == -1) {
av_log(avctx, AV_LOG_WARNING, "PPS not present in the stream,
nor in AVCC, stream may be unreadable\n");
if ((ret = alloc_and_copy(poutbuf, poutbuf_size,
--
2.4.1
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