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"
30 typedef struct H264BSFContext {
40 static int alloc_and_copy(AVPacket *out,
41 const uint8_t *sps_pps, uint32_t sps_pps_size,
42 const uint8_t *in, uint32_t in_size)
44 uint32_t offset = out->size;
45 uint8_t nal_header_size = offset ? 3 : 4;
48 err = av_grow_packet(out, sps_pps_size + in_size + nal_header_size);
53 memcpy(out->data + offset, sps_pps, sps_pps_size);
54 memcpy(out->data + sps_pps_size + nal_header_size + offset, in, in_size);
56 AV_WB32(out->data + sps_pps_size, 1);
58 (out->data + offset + sps_pps_size)[0] =
59 (out->data + offset + sps_pps_size)[1] = 0;
60 (out->data + offset + sps_pps_size)[2] = 1;
66 static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
68 H264BSFContext *s = ctx->priv_data;
70 uint64_t total_size = 0;
71 uint8_t *out = NULL, unit_nb, sps_done = 0,
72 sps_seen = 0, pps_seen = 0;
73 const uint8_t *extradata = ctx->par_in->extradata + 4;
74 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
75 int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
77 s->sps_offset = s->pps_offset = -1;
79 /* retrieve sps and pps unit(s) */
80 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
91 unit_size = AV_RB16(extradata);
92 total_size += unit_size + 4;
93 if (total_size > INT_MAX - padding) {
94 av_log(ctx, AV_LOG_ERROR,
95 "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n");
97 return AVERROR(EINVAL);
99 if (extradata + 2 + unit_size > ctx->par_in->extradata + ctx->par_in->extradata_size) {
100 av_log(ctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
101 "corrupted stream or invalid MP4/AVCC bitstream\n");
103 return AVERROR(EINVAL);
105 if ((err = av_reallocp(&out, total_size + padding)) < 0)
107 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
108 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
109 extradata += 2 + unit_size;
111 if (!unit_nb && !sps_done++) {
112 unit_nb = *extradata++; /* number of pps unit(s) */
114 s->pps_offset = total_size;
121 memset(out + total_size, 0, padding);
124 av_log(ctx, AV_LOG_WARNING,
125 "Warning: SPS NALU missing or invalid. "
126 "The resulting stream may not play.\n");
129 av_log(ctx, AV_LOG_WARNING,
130 "Warning: PPS NALU missing or invalid. "
131 "The resulting stream may not play.\n");
133 av_freep(&ctx->par_out->extradata);
134 ctx->par_out->extradata = out;
135 ctx->par_out->extradata_size = total_size;
140 static int h264_mp4toannexb_init(AVBSFContext *ctx)
142 H264BSFContext *s = ctx->priv_data;
143 int extra_size = ctx->par_in->extradata_size;
146 /* retrieve sps and pps NAL units from extradata */
148 (extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) ||
149 (extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) {
150 av_log(ctx, AV_LOG_VERBOSE,
151 "The input looks like it is Annex B already\n");
152 } else if (extra_size >= 6) {
153 ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE);
157 s->length_size = ret;
161 s->extradata_parsed = 1;
163 av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size);
164 return AVERROR_INVALIDDATA;
170 static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out)
172 H264BSFContext *s = ctx->priv_data;
177 uint32_t cumul_size = 0;
179 const uint8_t *buf_end;
183 ret = ff_bsf_get_packet(ctx, &in);
187 /* nothing to filter */
188 if (!s->extradata_parsed) {
189 av_packet_move_ref(out, in);
196 buf_end = in->data + in->size;
199 ret= AVERROR(EINVAL);
200 if (buf + s->length_size > buf_end)
203 for (nal_size = 0, i = 0; i<s->length_size; i++)
204 nal_size = (nal_size << 8) | buf[i];
206 buf += s->length_size;
207 unit_type = *buf & 0x1f;
209 if (nal_size > buf_end - buf || nal_size < 0)
213 s->idr_sps_seen = s->new_idr = 1;
214 else if (unit_type == 8) {
215 s->idr_pps_seen = s->new_idr = 1;
216 /* if SPS has not been seen yet, prepend the AVCC one to PPS */
217 if (!s->idr_sps_seen) {
218 if (s->sps_offset == -1)
219 av_log(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
221 if ((ret = alloc_and_copy(out,
222 ctx->par_out->extradata + s->sps_offset,
223 s->pps_offset != -1 ? s->pps_offset : ctx->par_out->extradata_size - s->sps_offset,
232 /* if this is a new IDR picture following an IDR picture, reset the idr flag.
233 * Just check first_mb_in_slice to be 0 as this is the simplest solution.
234 * This could be checking idr_pic_id instead, but would complexify the parsing. */
235 if (!s->new_idr && unit_type == 5 && (buf[1] & 0x80))
238 /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
239 if (s->new_idr && unit_type == 5 && !s->idr_sps_seen && !s->idr_pps_seen) {
240 if ((ret=alloc_and_copy(out,
241 ctx->par_out->extradata, ctx->par_out->extradata_size,
245 /* if only SPS has been seen, also insert PPS */
246 } else if (s->new_idr && unit_type == 5 && s->idr_sps_seen && !s->idr_pps_seen) {
247 if (s->pps_offset == -1) {
248 av_log(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
249 if ((ret = alloc_and_copy(out, NULL, 0, buf, nal_size)) < 0)
251 } else if ((ret = alloc_and_copy(out,
252 ctx->par_out->extradata + s->pps_offset, ctx->par_out->extradata_size - s->pps_offset,
256 if ((ret=alloc_and_copy(out, NULL, 0, buf, nal_size)) < 0)
258 if (!s->new_idr && unit_type == 1) {
267 cumul_size += nal_size + s->length_size;
268 } while (cumul_size < buf_size);
270 ret = av_packet_copy_props(out, in);
276 av_packet_unref(out);
282 static const enum AVCodecID codec_ids[] = {
283 AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
286 const AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
287 .name = "h264_mp4toannexb",
288 .priv_data_size = sizeof(H264BSFContext),
289 .init = h264_mp4toannexb_init,
290 .filter = h264_mp4toannexb_filter,
291 .codec_ids = codec_ids,