[FFmpeg-devel] [PATCH 5/6] avfilter/dnn/dnn_backend_tf: simplify the code with ff_hex_to_data

[James Almer]

On 4/26/2021 7:48 AM, lance.lmwang at gmail.com wrote:
> From: Limin Wang <lance.lmwang at gmail.com>
> 
> please use tools/python/tf_sess_config.py to get the sess_config after that.
> note the byte order of session config is the normal order.
> 
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>   libavfilter/dnn/dnn_backend_tf.c | 34 ++++++----------------------------
>   1 file changed, 6 insertions(+), 28 deletions(-)
> 
> diff --git a/libavfilter/dnn/dnn_backend_tf.c b/libavfilter/dnn/dnn_backend_tf.c
> index fb799d2..0084157 100644
> --- a/libavfilter/dnn/dnn_backend_tf.c
> +++ b/libavfilter/dnn/dnn_backend_tf.c
> @@ -28,6 +28,7 @@
>   #include "dnn_backend_native_layer_conv2d.h"
>   #include "dnn_backend_native_layer_depth2space.h"
>   #include "libavformat/avio.h"
> +#include "libavformat/internal.h"
>   #include "libavutil/avassert.h"
>   #include "../internal.h"
>   #include "dnn_backend_native_layer_pad.h"
> @@ -202,35 +203,21 @@ static DNNReturnType load_tf_model(TFModel *tf_model, const char *model_filename
>       TF_SessionOptions *sess_opts;
>       const TF_Operation *init_op;
>       uint8_t *sess_config = NULL;
> -    int sess_config_length = 0;
> +    int sess_config_length = ff_hex_to_data(NULL, tf_model->ctx.options.sess_config + 2);

This is a lavf internal function. You can't use it here.

Please revert this patch, or make a copy of this function to be used in 
lavfi.

>   
>       // prepare the sess config data
>       if (tf_model->ctx.options.sess_config != NULL) {
>           /*
>           tf_model->ctx.options.sess_config is hex to present the serialized proto
>           required by TF_SetConfig below, so we need to first generate the serialized
> -        proto in a python script, the following is a script example to generate
> -        serialized proto which specifies one GPU, we can change the script to add
> -        more options.
> -
> -        import tensorflow as tf
> -        gpu_options = tf.GPUOptions(visible_device_list='0')
> -        config = tf.ConfigProto(gpu_options=gpu_options)
> -        s = config.SerializeToString()
> -        b = ''.join("%02x" % int(ord(b)) for b in s[::-1])
> -        print('0x%s' % b)
> -
> -        the script output looks like: 0xab...cd, and then pass 0xab...cd to sess_config.
> +        proto in a python script, tools/python/tf_sess_config.py is a script example
> +        to generate the configs of sess_config.
>           */
> -        char tmp[3];
> -        tmp[2] = '\0';
> -
>           if (strncmp(tf_model->ctx.options.sess_config, "0x", 2) != 0) {
>               av_log(ctx, AV_LOG_ERROR, "sess_config should start with '0x'\n");
>               return DNN_ERROR;
>           }
>   
> -        sess_config_length = strlen(tf_model->ctx.options.sess_config);
>           if (sess_config_length % 2 != 0) {
>               av_log(ctx, AV_LOG_ERROR, "the length of sess_config is not even (%s), "
>                                         "please re-generate the config.\n",
> @@ -238,21 +225,12 @@ static DNNReturnType load_tf_model(TFModel *tf_model, const char *model_filename
>               return DNN_ERROR;
>           }
>   
> -        sess_config_length -= 2; //ignore the first '0x'
> -        sess_config_length /= 2; //get the data length in byte
> -
> -        sess_config = av_malloc(sess_config_length);
> +        sess_config = av_mallocz(sess_config_length + AV_INPUT_BUFFER_PADDING_SIZE);
>           if (!sess_config) {
>               av_log(ctx, AV_LOG_ERROR, "failed to allocate memory\n");
>               return DNN_ERROR;
>           }
> -
> -        for (int i = 0; i < sess_config_length; i++) {
> -            int index = 2 + (sess_config_length - 1 - i) * 2;
> -            tmp[0] = tf_model->ctx.options.sess_config[index];
> -            tmp[1] = tf_model->ctx.options.sess_config[index + 1];
> -            sess_config[i] = strtol(tmp, NULL, 16);
> -        }
> +        ff_hex_to_data(sess_config, tf_model->ctx.options.sess_config + 2);
>       }
>   
>       graph_def = read_graph(model_filename);
>