2 * H.264 MP4 to Annex B byte stream format filter
3 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/mem.h"
28 typedef struct H264BSFContext {
38 static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
39 const uint8_t *sps_pps, uint32_t sps_pps_size,
40 const uint8_t *in, uint32_t in_size)
42 uint32_t offset = *poutbuf_size;
43 uint8_t nal_header_size = offset ? 3 : 4;
46 *poutbuf_size += sps_pps_size + in_size + nal_header_size;
47 if ((err = av_reallocp(poutbuf,
48 *poutbuf_size + FF_INPUT_BUFFER_PADDING_SIZE)) < 0) {
53 memcpy(*poutbuf + offset, sps_pps, sps_pps_size);
54 memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size);
56 AV_WB32(*poutbuf + sps_pps_size, 1);
58 (*poutbuf + offset + sps_pps_size)[0] =
59 (*poutbuf + offset + sps_pps_size)[1] = 0;
60 (*poutbuf + offset + sps_pps_size)[2] = 1;
66 static int h264_extradata_to_annexb(H264BSFContext *ctx, AVCodecContext *avctx, const int padding)
69 uint64_t total_size = 0;
70 uint8_t *out = NULL, unit_nb, sps_done = 0,
71 sps_seen = 0, pps_seen = 0;
72 const uint8_t *extradata = avctx->extradata + 4;
73 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
74 int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
76 ctx->sps_offset = ctx->pps_offset = -1;
78 /* retrieve sps and pps unit(s) */
79 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
90 unit_size = AV_RB16(extradata);
91 total_size += unit_size + 4;
92 if (total_size > INT_MAX - padding) {
93 av_log(avctx, AV_LOG_ERROR,
94 "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n");
96 return AVERROR(EINVAL);
98 if (extradata + 2 + unit_size > avctx->extradata + avctx->extradata_size) {
99 av_log(avctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
100 "corrupted stream or invalid MP4/AVCC bitstream\n");
102 return AVERROR(EINVAL);
104 if ((err = av_reallocp(&out, total_size + padding)) < 0)
106 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
107 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
108 extradata += 2 + unit_size;
110 if (!unit_nb && !sps_done++) {
111 unit_nb = *extradata++; /* number of pps unit(s) */
113 ctx->pps_offset = (extradata - 1) - (avctx->extradata + 4);
120 memset(out + total_size, 0, padding);
123 av_log(avctx, AV_LOG_WARNING,
124 "Warning: SPS NALU missing or invalid. "
125 "The resulting stream may not play.\n");
128 av_log(avctx, AV_LOG_WARNING,
129 "Warning: PPS NALU missing or invalid. "
130 "The resulting stream may not play.\n");
132 av_free(avctx->extradata);
133 avctx->extradata = out;
134 avctx->extradata_size = total_size;
139 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
140 AVCodecContext *avctx, const char *args,
141 uint8_t **poutbuf, int *poutbuf_size,
142 const uint8_t *buf, int buf_size,
145 H264BSFContext *ctx = bsfc->priv_data;
149 uint32_t cumul_size = 0;
150 const uint8_t *buf_end = buf + buf_size;
153 /* nothing to filter */
154 if (!avctx->extradata || avctx->extradata_size < 6) {
155 *poutbuf = (uint8_t *)buf;
156 *poutbuf_size = buf_size;
160 /* retrieve sps and pps NAL units from extradata */
161 if (!ctx->extradata_parsed) {
162 ret = h264_extradata_to_annexb(ctx, avctx, FF_INPUT_BUFFER_PADDING_SIZE);
165 ctx->length_size = ret;
167 ctx->idr_sps_seen = 0;
168 ctx->idr_pps_seen = 0;
169 ctx->extradata_parsed = 1;
175 ret= AVERROR(EINVAL);
176 if (buf + ctx->length_size > buf_end)
179 for (nal_size = 0, i = 0; i<ctx->length_size; i++)
180 nal_size = (nal_size << 8) | buf[i];
182 buf += ctx->length_size;
183 unit_type = *buf & 0x1f;
185 if (buf + nal_size > buf_end || nal_size < 0)
189 ctx->idr_sps_seen = ctx->new_idr = 1;
190 else if (unit_type == 8) {
191 ctx->idr_pps_seen = ctx->new_idr = 1;
192 /* if SPS has not been seen yet, prepend the AVCC one to PPS */
193 if (!ctx->idr_sps_seen) {
194 if (ctx->sps_offset == -1)
195 av_log(avctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
197 if ((ret = alloc_and_copy(poutbuf, poutbuf_size,
198 avctx->extradata + ctx->sps_offset,
199 ctx->pps_offset != -1 ? ctx->pps_offset : avctx->extradata_size - ctx->sps_offset,
202 ctx->idr_sps_seen = 1;
208 /* if this is a new IDR picture following an IDR picture, reset the idr flag.
209 * Just check first_mb_in_slice to be 0 as this is the simplest solution.
210 * This could be checking idr_pic_id instead, but would complexify the parsing. */
211 if (!ctx->new_idr && unit_type == 5 && (buf[1] & 0x80))
214 /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
215 if (ctx->new_idr && unit_type == 5 && !ctx->idr_sps_seen && !ctx->idr_pps_seen) {
216 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
217 avctx->extradata, avctx->extradata_size,
221 /* if only SPS has been seen, also insert PPS */
222 } else if (ctx->new_idr && unit_type == 5 && ctx->idr_sps_seen && !ctx->idr_pps_seen) {
223 if (ctx->pps_offset == -1) {
224 av_log(avctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
225 if ((ret = alloc_and_copy(poutbuf, poutbuf_size,
226 NULL, 0, buf, nal_size)) < 0)
228 } else if ((ret = alloc_and_copy(poutbuf, poutbuf_size,
229 avctx->extradata + ctx->pps_offset, avctx->extradata_size - ctx->pps_offset,
233 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
234 NULL, 0, buf, nal_size)) < 0)
236 if (!ctx->new_idr && unit_type == 1) {
238 ctx->idr_sps_seen = 0;
239 ctx->idr_pps_seen = 0;
245 cumul_size += nal_size + ctx->length_size;
246 } while (cumul_size < buf_size);
256 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
257 .name = "h264_mp4toannexb",
258 .priv_data_size = sizeof(H264BSFContext),
259 .filter = h264_mp4toannexb_filter,